#mercercest

CONTAINS: hoo boy, where do I fucking start? genderless blacklight reader (it/they); 4k words of pure filth; porn no plot; the reader talks in this as it’s gained more coherence, but it pretends not being able to at first; the reader has a nickname (Chi, from Chimera, it’s literally just used once); weird virus incest; mercercest but also make it incest; consent is implied non-verbally – xander is just an asshole; double penetration in one hole (alex + xander → reader); breeding kink (alex + reader); blowjob (reader → xander); overstimulation (xander); innapropriate use of belts (leash + tying someone up: reader → xander); choking (alex + xander → reader, reader → xander); tendrils; cutting (alex → reader); stabbing (alex → reader); anal prep (reader → xander); anal (alex → xander); profanity (the worst of them all fr: xander + alex); pain kink (reader); gagging (xander → reader, reader → xander); knotting (alex → xander); alex enjoying fucking his brother and child and not denying it one bit; alex and reader using nonhuman sounds to secretly communicate; cowgirl position (reader → xander); harsh bite marks and bruises (reader → xander); alex bites chunks out of the reader oops; reader clawing at xander’s chest; nipple sucking (reader → xander, alex’s tendrils → reader); xander loses his mind; xander trying to hide he likes being handled roughly and failing; quite a lot of cum; aftercare (99.5% reader + 0.5% alex → xander); everyone is a slut in here, no exceptions; dana is mentioned briefly; the reader loves to take care of it's humans :); the ending is actually pretty soft in my opinion. GOD i hope i didnt miss anything

You are back in Xander’s lab for today. Said he wanted to test something now that you’ve got enough biomass to form your body properly. Alex was here too, he brought you here at his brother's request but unlike last time, he didn’t leave you two alone.

Though, maybe a little bit of clarification on what he wanted to “test” your body for would’ve been nice… you were expecting something combat related, not this. You also expected Alex to complain, but instead he agreed with his brother.

“Knees,” the doctor tells you while pushing you down by the shoulder. You obey him, getting on your knees before him. 

He takes his coat off and throws it away, uncaring what happens to it. He fumbles with his belt and he takes it off, kneeling down in front of you. He takes your wrists in his hands and binds them together with the belt, leaving your bound arms in your lap.

As he takes his clothes off, Alex kneels behind you, pushing his hands below your shirt. He barely touches you, his hands barely grazing your skin as he caresses your chest up and down.

The fleeting sensation makes your body shiver, goosebumps appearing across your skin and you close your eyes, trying to savor it in. The moment doesn’t last long however, because Xander tilts your head up by your hair, his cock out and in front of your mouth. He gives it a few pumps to harden it fully, and one of Alex’s hands comes up to your chin, forcing your mouth to open for his brother.

You stick your tongue out. You know what to do, you’ve done this with him before. Though you assume things will be a bit different now, since this time you’re bound and your King is here too. He puts his tip on your tongue, not moving any further, and Alex moves your head forward for you. 

You reach the base easily, the body you’ve made for yourself lacking a gag reflex. And like last time, you make your tongue longer, wrapping it around Xander’s cock and jerking him off as you deepthroat him. Alex takes the reins, moving your head up and down Xander’s cock for you.

To make up for the slow pace, Xander starts fucking your face, pulling your head even further back so he can reach deeper inside. Alex brings his other hand to his mouth, coating two fingers in his saliva. He then reaches down your pants with them, searching for your hole, all while maintaining your pace.

He shoves his fingers inside, working to open you up for them. The action makes you gasp and moan around Xander’s cock, your throat tightening in the process. There’s a visible bulge in your throat, and Alex lets go of your head to choke you.

Xander takes the opportunity to grab fistfuls of your hair and he moves you as he pleases, fucking you even faster than before. You try to contribute by wrapping your tongue tighter against his shaft, massaging the veins on each side of his cock while the tip of your tongue dipped into his slit each time he pulled back.

Unlike last time you sucked him off, Xander doesn’t moan this time, which bums you out a little bit. He instead muffles his sounds and groans whenever he feels a moan threatening to come out of him. You liked hearing his moans, could it be because Alex is here?

There’s a faint growl coming out of you, which makes Alex go still. You were asking him to let Xander inside you, non-verbally. He pulls his fingers out and stops his brother from continuing his blowjob.

“What?” He grits out, clearly pissed off that Alex stopped him.

“It’s ready,” he tells him. It takes Xander 2 seconds to process what he said, but when he does, he takes the rest of his clothes off.

Alex doesn’t bother with your own however. He forms a pair of claws and just tears them into shreds, throwing them to the side. You growl at him again, this time in an angry way. Those were your clothes, damn it! 

Alex picks you up off the ground and positions you so that you are held up entirely by him. His arms hooked under your thighs, your back against his chest as he knelt on the floor. When Xander is done undressing, he kneels in front of you, facing you two, and Alex drapes your legs over his thighs as the three of you press together. His brother takes your bound-wrists and he wraps them around his neck.

Xander positions his cock at the front of your entrance, teasing you by rubbing the tip of his cock alongside it. You feel Alex’s mass shift behind you, undressing himself as he lets go of one of your legs, coating his fingers in your saliva again. As he moves his fingers back and forth inside your mouth, you feel Xander push inside you. 

When he reaches halfway in, he stops and he pulls back. As Xander moves forward in you again, your King’s fingers leave your mouth, and he pumps his cock to lubricate himself. When he’s done, he grabs you by the thigh again.

Xander pulls out to the tip, and that’s when Alex positions himself at your entrance too. This time, both of them push inside you at the same time. Neither of them stop halfway, pushing in as deep as they can. You almost scream out at the feeling of your hole being stretched so much so suddenly. As much as Alex loves you, he can’t let you be too loud, so he silences you with one of his tentacles.

Your King remains still inside, while Xander has started to fuck you earnestly. He lowers down and he bites and suckles at your nipples, collarbones and neck, though he’s incapable of leaving behind marks on you, your healing abilities not giving him that satisfaction. Alex also starts biting on your shoulder and the back of your neck, though he bites chunks out of you which makes you whimper, the pain feels way too good.

As Xander started to pick up the pace to chase his pleasure, Alex started to move inside you too, though his pace was very slow. Neither of them caring about your pleasure but that thought gave you a high instead. 

All of a sudden, you feel Alex push you into Xander’s lap. You can also feel him pull out, and then you hear him retreat. When you look for Alex, he’s grabbing your and Xander’s belts. There are a few inhuman sounds coming out of him as he does so, communicating with you. Oh, that’s a really nice idea.

You take a hold of Xander’s neck and push the doctor on his back, a bit too hard, as there’s a thud that follows afterwards. 

“The fuck–”

“Doctor.” This is the first time he hears you speak with no guidance. The voice that comes out of you is nowhere near human. It’s loud and layered, as if there’s more than one person talking at once. It makes him go still.

Your King comes back, and gives you the belts before he sits behind you. You take one of the belts and you close it around Xander’s neck, tugging on the make-shift leash to bring his head up a little.

“Who’s the dog now?”

“Who are you calling a ‘dog’, bitch?” he spits out, clearly annoyed at your actions and words. You were going to let his arms be free, but now you cannot let such behavior go unpunished. You let go of the leash and forcefully take his hands off your hips. Grabbing the other belt, you tie his wrists together and above his head.

“You fucking–” You don’t let him talk. You lean forward and bite his lower lip till he bleeds. He can curse you out as much as he wants, but you know it’s just pointless chatter. His dick is still inside you, you literally felt it twitch at the rough handling. He’s just a fucking brat. 

“Hey.” Alex drags your attention back to him. Right. You let Xander’s lip go, and a tendril shoots out of your back, moving to your mouth, and you take it inside its tip. You coat it with as much saliva as you can, before you slowly move it towards Xander’s hole. You slowly push it in, trying to prep him, and you hear a gasp coming out of him.

You cover his mouth with your hand. He can save the complaints for later, right now you and your King have a mission: ruin him. It’s what he deserves for getting his hands on you first – Alex’s words. 

You pump the tendril in and out of him for a good few minutes, all the while Alex is spreading your leftover slick over his cock for better lubrication.

“I think he’s good now,” you say. You couldn’t see his hole for yourself, but from the way his muffled sounds went from pained groans to moaning under your hand, it probably wasn’t a terrible guest.

“Yeah, he’s fine. Get off a bit, I need to get him in a better position for us,” Alex instructs you. You move off Xander, pulling him out of you and move aside to let Alex do his thing. 

For someone with so much bite in his words, he’s completely pliant as his brother grabs him by the legs to pull him closer towards him. 

“No protests?” Alex questions Xander, and the doctor just gives him a muffled “fuck off,” but he still doesn’t show any sign of actual resistance. He doesn’t bite your hand, doesn’t kick Alex away, nothing. Not that it would do anything, but still.

“Last warning, doctor. No protests?” You ask him as well. The goal is to mess him up, yes, but you don’t want to violate him either (you don’t want to, at the very least, you don’t know what Alex thinks). He just gives you the dirtiest look he could muster as Alex’s tip was rubbing against him. However, that was still not a “no.”

Alex takes that as a sign to push himself inside slowly. You could see the doctor’s face, watching how his eyes were rolling to the back of his head the more Alex kept going. As Alex’s pelvis meets his brother’s ass, he calls out for you. You turn to face him, and you see Alex’s face full of restraint.

“Get back on him,” he instructs you again. “Stick to his chest.”

And once again, you do as you are told. You move back on Xander, finally letting his mouth go, and you hover above his hard cock, guiding it back inside you. 

“You two are fucking freaks,” Xander gasps out, before adding “Especially you, Alex. I turned a blind eye to you wanting to fuck your literal child. You’re a virus and it was made by you, it made sense in some fucked up way. But your maker and brother? You’re just insane at that point.”

“Thanks, but I didn’t hear shit coming from you when we were rubbing dicks inside my child. Mute him again, I don’t need a moral lesson while I’m fucking him.” Instead of covering his mouth with your hand this time, you extend a tendril out and grab Xander’s shirt, ripping a part off it so you could gag him with it.

“Fucker, and you dared to call yourself better than–” His sentence cuts off as you gag him. You loop the belt from his neck around one of your arms and lay down on his chest. As you pull on the leash to choke him, you begin to move up and down his cock. You set a slow pace, the position is a bit awkward for you. You also did not want to break him before Alex could participate. 

Alex also begins to retreat out of Xander, leaving only the tip before slamming right back in. He repeats that action for a while before he sets a faster pace than yours, fucking his brother frantically. 

Alex’s pace made Xander buck up and grind against you in tandem with your thrusts. You lick and bite at the doctor’s neck and collarbones harshly, leaving behind bleeding bite marks and bruises that will probably last weeks with how purple they looked like.

You could hear Xander moan aloud behind the gag from the sudden assault on his body. You glanced up at him, and he looked like a total mess: his head was to the side, eyes closed. Drool was coming out of him, staining the shirt in his mouth and trailing down his chin and slowly down his neck as well. He also had tears in his eyes. If you were in a better position, you would’ve licked them off his pretty face.

You lick off the drool that was going down his neck instead, pressing down on his Adam’s apple from beneath the belt with your tongue. 

“Chi, up,” you hear Alex tell you, his voice breathy. You stand on your forearms, but it wasn’t enough it seemed. Alex straightens you up by pushing you by the stomach, and you let go of Xander’s leash.

“Look at me,” and you turn your head around. As you do, a few tendrils latch on and hold onto your face and they angle you in a way so he can kiss you. The kiss is deep, his tongue mapping the inside of your mouth hungrily. This position made you stop riding Xander but you could still feel him thrusting in and out of you as best as he could, though the lack of proper friction on his dick made him whine. Alex didn’t stop fucking his brother for even one second, he seemed to go faster at it actually.

Xander’s whining caught your attention, and even when Alex growls at you for taking your attention off him, you turn back to Xander. His brows were furrowed, he was sweaty all over, and his dick inside you was twitching and throbbing constantly. Ah, he must be close. You begin riding him again, faster this time, grabbing the leash again and pulling him by it. One of Alex’s tendrils that were holding your face entered your hole and wrapped itself around Xander’s dick, jerking him off with it. You claw at his chest with your other hand, lowering yourself just enough to suck and bite at his nipples as well. You needed him to come inside you.

It didn’t take long afterwards for him to cum. He came hard, and a lot. He filled you to the brim as both you and Alex continued fucking him as hard and as fast as you two could. There is a small bump on your stomach now. 

But there wasn’t enough stimulation for you, which kinda pissed you off. You tried riding him harder, but that didn’t work out either. You barely catch Alex’s annoyed groan behind you, apparently you weren’t the only one mad at your situation.

“Come on, you didn’t have such a hard time when I had you last time,” he said, more tendrils coming out of him, wrapping themselves around your chest. Two of them latched on to your nipples, sucking and twisting them around, while the other few shifted into sharp blades, cutting your chest with them. You could feel your orgasm building up slowly now, the hand that was clawing at Xander’s chest rising to your throat to choke yourself out.

But it still wasn’t enough. You drop the leash and you press down on your stomach so you can feel Xander’s dick better. He had softened inside you, shooting blanks as your greedy hole took everything he had. 

“I… I can’t. My King, I can’t!” You whine out, tears forming at the corner of your eyes.

Well, that would just not do. Alex let go of one of his brother’s legs so that he could shift it into a pair of claws. He stabs you through the chest with them, and the pain that accompanied the action did it for you. You came with a silent scream, the sudden orgasm not giving your brain enough time to process what was going on. 

He takes out his claws from your chest and morphs them back to his human arm, going back to holding onto Xander’s leg as support. You collapsed onto the doctor’s chest, breathing heavily alongside him. You shakily bring your right hand to the belt surrounding his neck, cutting it in half. You do the same for his gag and wrist-binds. Free from them, you can hear his whimpers even better now.

God he was so loud. You should’ve recorded him to show him later just how much he enjoyed getting fucked by his creations. His now unbound arms wrap around your chest, scratching as deeply as he could into your back as a way to anchor himself. You let him do as he pleased, kissing the hollow of his throat as soft purrs come out of you in hopes of comforting him a bit. 

Now that you finished, Alex could position Xander in a better way. He grabbed his legs and put them on his shoulders, fucking him deeper than before. Seeing the both of you so ruined made him euphoric, he was nearing his orgasm. 

He shifts his dick, forming a knot at the base. If he was going to cum inside his darling creator and brother, he might as well do it properly. A few more rapid thrusts later, and he shoves his knot inside Xander, breeding his brother in the process. 

He stills, grinding against him, watching as Xander’s body shook violently from what he’d just done to him. They’re going to be stuck for a while, so Alex shifts the rest of his body in a way so he can lean forward and lay down on your back.

You steal a glance at Xander, and somehow he’s still awake, just breathing extremely heavily below you. Honestly, you find it pretty admirable how Xander managed to not pass out just yet.

The three of you sat like that for maybe 25 minutes. You tried to keep count, but Xander’s whining and whimpering made it a bit hard for you to do so. When the knot deflated, Alex pulled himself out of Xander, and walked over to whatever clothes were left intact and then to the nearest sink, grabbing a beaker on the way there.

“Doctor? Are you okay?” You ask him, curious if he needed anything.

“Get off. Please,” he begs of you, and only then do you realize you’ve been cockwarming him ever since you came. You take his dick out of you and you sit down on his hips. You take his wrists in your hands and you begin massaging the sore spots. 

Alex comes back with a beaker filled with water and Xander’s shirt, which he got wet enough to act as a wipe. He hands them over to you as he sits down next to the two of you, clothes shifting back on his body.

You take the shirt and start wiping Xander’s face with it in soft strokes. You then move to his throat, also massaging the spot where the belt was. Then came his chest and stomach, you had to move off him and you sat next to Alex. You gently cleaned his genitals off, then his hole, and then his thighs, which you also massaged a little bit to stop them from shaking as much. 

When you turned back around, Xander had one of his arms draped over his eyes, his breathing evening out.

“Do you want some water?” You ask him, and he looks at you with just one eye poking out behind his arm and he nods his head yes.

You help him sit up, holding the beaker to his face to help him drink. Once he finished drinking, he collapsed into your chest. You hugged him, rubbing random symbols onto his back and shoulder blades. You looked over at Alex, and he was just watching you take care of his brother.

‘What now?’ You chirped out, making sure Xander didn’t understand you. 

‘Bed. He needs to rest properly. I’ll bring you two clothes, wait here.’ He says back to you, already half way through the exit mid-sentence. 

You and Xander sit like that for a while. Alex leaving felt deliberate… like he wanted you two to be alone for a moment. 

“Why are you still here?” you hear him say after a while.

“Huh?”

“I said, ‘Why are you still here?’ You got what you wanted, no?” He repeats himself. Did he really think you’d just leave him on the floor like that? That’s sad. You’re not like that at all. 

“Alex is bringing us clothes so you can go to bed and rest.” You explain, telling him what you spoke with your King.

“Uh-huh.” 

“How are you feeling?” You shift the conversation towards him. He still hasn’t pulled away from your embrace.

“Oh, absolutely perfect. I just got railed by my brother and his kid. A regular Tuesday, honestly.” Of course he couldn’t help himself to not say something smartass-y.

“If you can be sarcastic, then you’re okay,” you tell him and you hug him tighter. And it was somewhat true. He was sore (not as sore as he should’ve been, thanks to your massages), and his brain cells haven’t fully come back to him yet, but it could’ve been worse.

The silence returns, and you two keep cuddling. You start kissing over the marks you left on his body, licking over them as well. You hear him sigh, and he melts into your embrace. It isn’t until Alex comes back that Xander lifts his head off your shoulders. 

“And here I was hoping you’d get blown up. What a shame,” he says to him, annoyance clear in his voice.

“What a shame, indeed. I’ve got you two clothes.” He gives them to you, and you move Xander off you so you can help him dress up. It was a pair of sweatpants and a plain black T-shirt.

“Oh, how sweet. You can fuck off now, thank you.”

He doesn’t, instead Alex takes a seat in one of the lab’s chairs, kicking another in your direction. You help Xander sit down in the chair so you could put the pants on him easier and he puts the shirt on while you do so. Then you give him his shoes and coat, and start dressing yourself up too. 

When you finish, you pick up Xander piggyride-style, ignoring his protests, and you follow Alex as he gets up and leaves.

You three arrive home very late, with the sky being pitch black. Alex opens the door slowly and you put Xander down.

“Dana better be fucking asleep,” he whispers. And now that he brings her up, you hope so too. You haven’t met her officially just yet, but you don’t think that meeting her now would go too well since you just came back from fucking her brothers.

Alex enters the apartment and settles on the couch in the living room, turning on the TV. You guide his brother to his room, listening out for any movement from their sister, but besides Alex searching for a channel to watch on TV, it’s pretty quiet.

Idea / Mercercest

Xander, that man is a whore

Yandere Xander

Idea / Xander

Yandere Xander

Xander does this