Neural Substrates - Spencer Reid
╰summary: Spencer and you have been dating for a few weeks now. When he sees how Luke makes you laugh, he cannot really describe what he is feeling. Surely it cannot be jealousy, right? ╰pairing: Spencer x reader ╰Warnings: jealous!Spencer, bau!reader, reader and Spencer are not yet in an established relationship, insecure!Spencer, Spencer just doesn't want to do anything wrong and is scared he's losing reader, angst/comfort with a fluff ending ╰word count: 1.4k જ⁀➴Masterlist
On a Friday night, the bullpen was quieter than it usually was. It seemed even FBI agents occasionally wanted to spend their weekends somewhere other than their work place. Against the relative silence, the fluorescent lights above were somehow humming louder than they regularly were.
Spencer was deep in thought, with a pile of case files lying next to him and his mind scanning the pages a little slower than the rapid speed he was used to. Apparently, even a genius was tired sometimes and in desperate need of a well rested sleep and weekend.
Maybe his lack of sleep was why he didn't notice it at first. The giggling. The joking. The hushed voices.
With a rushed look at his watch, he sat up straight in his chair and stretched his back, scanning his surroundings for the first time in hours. It wasn't hard to spot you, though it never really was. Spencer's eyes were somehow always drawn to your frame earlier than they spotted anything else in any given room.
Warmth spread through his chest, and up his neck into his cheeks, and he instinctively shook his head as if rid himself of it. He was still trying to get used to the bodily reactions occurring every time he laid eyes on you.
The two of you had only been dating for a few weeks, and everything surrounding the dating etiquette was still very much new to him. It was no secret that Spencer loved learning new facts about all kinds of different things. But with you, he was oftentimes more tense than excited; too afraid that he'd do something wrong and ruin what the both of you had.
Spencer watched as you threw your head back laughing, and then discovered the source of your delight - you were laughing at something Luke Alvez had said, the both of you deep in a joyous conversation. Spencer's eyes now drifted to Luke, and he noticed how his eyes, too, were filled with delight and appreciation for you. It seemed like he couldn't take his eyes off of you; a feeling Spencer was all too familiar with.
An uncomfortable feeling arose in the pit of Spencer's stomach. It felt as though his intestines were spasming and were brewing up a kind of anger Spencer had never experienced before. It was slowly but surely burning a hole into his abdomen.
Without noticing it, his hands had gripped harshly around the armrests of his chair, and his jaw clenched uncomfortably. He watched in horror as you leaned forward, still gasping from laughing so hard, and grabbed one of Luke's forearms for support.
He couldn't face the situation unfolding in front of him, so he averted his eyes. In a rush, he pushed the remaining files aside and turned off his computer, before he rose from his desk and all but stomped over to you and Luke.
''Hey, Reid we were just-'', Spencer cut Luke off without caring what he was trying to say. ''Are you ready to go?'', Spencer asked, gaze only fixed on you. The smile that had previously adorned your lips sank away, and Spencer could feel the mood between the three of you shift.
Luke's eyes switched awkwardly from you to Spencer and back again, trying to assess the situation and whether he should remove himself from it. Nobody from the team knew that Spencer and you were dating, so it was no surprise that Luke was even more bewildered concerning the wording of Spencer's question.
Your eyebrows furrowed in confusion and irritation as you scanned Spencer's face for clues as to what was going on. His gaze was much harder than what you were used to seeing in him, and his whole body seemed tense.
After a few moments of confused silence, you finally spoke. ''Sure...'', you mumbled, still uncertain, and shot Luke a clueless look, which he returned. You grabbed your bag from the floor as Spencer was returning to his desk to grab his.
The walk to the elevator was spent in utter silence, but as the elevator ride seemed to stretch the minutes unbearably long, you couldn't hold it in anymore. ''Care to explain what just happened?''
''Nothing happened.''
He didn't even look at you as he talked. You scoffed, not believing such an answer was coming out of the mouth of someone who was usually so eloquent.
''Spencer,'', you urged, turning to him and waiting for him to finally look at you.
He didn't.
You watched him pull his bottom lip in by his teeth, gnawing down on it in contemplation.
''What was so funny, anyway?'', he finally asked, shooting you a sideways glance but still not giving you his full attention.
''What?''
''You were laughing really loudly. Did Alvez tell a joke or something?''
Brows furrowed, you thought back to what you were laughing about when it finally dawned on you. On the one hand, relief washed over you, having finally figured out what had bothered Spencer. On the other hand, you could not believe Spencer was so worked up about something that had been more than harmless.
''You're jealous!", you almost exclaimed, and could barely hide the smirk on your lips.
His head whipped around at that, and he finally met your eyes.
''What? No?!'', his voice broke off a little just as the elevator announced you arrived on your destined floor.
Spencer all but fled out of the small room, but you were right on his heels.
''Yes you are!''
''Mullen defined jealousy as a perception of threat of loss of a valued relationship to a real or imagined rival which includes affective, cognitive and behavioral components.'', he stated, just as the two of you reached your car.
You fumbled for your keys inside of your bag, and when you finally found them, unlocked your car. Spencer got into the passenger seat in more of a hurry than you had ever seen him.
You silently rolled your eyes as he continued to ramble. Not because he was explaining something (you usually loved when he did that), but because he was trying to deceive what he was feeling by hiding behind the things he understood. You shut the door of the driver's side when you were finally sitting next to him in the silence of the car.
''In particular, a study by Marazitti found that pathological jealousy is associated with altered fronto-striatal circuitry, the ventral medial prefrontal cortex, thalamus, insula and amygdala.'', he continued.
''So? Just because you know the neural substrates of jealousy does not mean you can't experience it.'', you countered, facing him.
He was clutching his bag on his lap and was trying his best to stare straight ahead and not face you.
''But I've never experienced it,''
''That's not an exclusion criterion, Spence,''
Silence. You could see him struggling to come up with something else, could see his brain searching for more definitions and facts to divert your attention from the topic in hand.
''Look, all I'm saying is that it's nothing bad. It's normal, everyone knows the fee-''
''What I mean is I shouldn't be experiencing the feeling when I have no right to,'', he cut you off, making confusion lace your face once again.
''What? Why shouldn't you?''
''Because we're not in an exclusive relationship. You can do whatever you want,''
Unexpectedly, you heart twisted painfully at the words he said and what they were implying. Not an exclusive relationship. You cleared your throat.
''Well, jealousy can occur in any types of relationships. They don't have to be romantic. And also...'', you trailed off, and as your gaze was focused on your nails, you could finally feel Spencer's eyes on yours, making you look up again.
The sight of his auburn eyes calmed the nervousness that had made itself apparent in the pits of your stomach, and you took a deep breath before continuing.
''I basically live at your place, and we act like a couple almost all of the time. So I would have said we are in a relationship, except if that's something you don't want-''
''Of course I do!''
Relief flooded your system for the second time that night, and you tried your hardest not to giggle at his response like a teenager would have (you failed).
''You do?''
Spencer took your hands in his, raised them to his lips and kissed your knuckles, all the while still, and finally, holding eye contact.
''Of course I do. Why else do you think my body unlocked a completely new emotion for me?''
''So you were jealous!''
He rolled his eyes lovingly, and a soft laugh escaped your lips. He raised one of his hands and pulled you into him by the back of your neck. With your foreheads touching and breathing each other in, he mumbled ''I wasn't,''
''Spencer Reid, I can't believe it, you're not even blushing when you're lying!''
A grin spread onto Spencer's lips, and, eidetic memory and all, he could not recall ever smiling so widely.
''Okay, so maybe a little bit.'', he admitted, and before you could reply, he gently pulled you in for a kiss.

















