Tickling.

She couldn't pinpoint exactly when this first came to her knowledge. Probably Elsword or Aisha brought it up during one of the group's camping or, maybe, she happened to hear it from a villager along their journey.

The source, however, was of little importance for her understanding. A brief search was enough to figure out the meaning behind the term and its implications: touching someone in a way to induce a reaction. Simple, yes, but barely the tip of the iceberg, as Rena would say.

If she closed her fingers around one's wrist, it didn't tickle. If she pressed her palm against one's back, it also didn't tickle. It took Eve merely another try to understand that there was more to it than just touching and, as a researcher at heart, she wouldn't settle with incomplete explanation.

And as if the problems regarding the recreation of such effect wasn't enough, Eve was also faced with problems approaching the others about this matter. It didn't seem to be some sort of taboo, neither an inappropriate matter like sexual intercourse, but it still triggered reactions like uneasiness, most of the cases, or stuttering and blushing, in some more… reactive cases.

But, hopefully, Add would still be able to help her in this matter. Or so she hoped, until some signs of distress appeared on his face as soon as she asked him about it.

"But, your majesty— ahem, why… are you interested in that?" Add sighed, his brows furrowed.

"I'm not sure either," Eve responded quickly, her posture elegant as ever as she sat in front of him. The privacy the inn's room gave them seemed proper to have these discussions, so she couldn't see why this wouldn't be a good moment. "But the harder it seems to understand, the more my curiosity is piqued, so I was hoping you could assist me again."

"D-do you even understand what you are implying?" Add coughed, again, feeling something stir at the bottom of his stomach.

"Yes," she nodded, "I asked to tickle you."

Add pinched the bridge of his nose, knowing her perceptive gaze would soon catch on any micro reaction he would let slip. "And care to explain why I have to assist you with that, your majesty?"

"Documents show that tickling is a common display of playfulness and affection between relatives, friends and partners — which should apply to us in some degree. You're, therefore, the most fitting to the task, not to mention our history of collaborations befor—"

"In machinery research, yes, not— this," Add retorted, quickly biting down at his lower lip when he saw the way Eve flinched. Was she even aware of how cute she looked at that moment? Was it on purpose or something her emotional module picked on? "…I'm sorry, I didn't mean to startle you."

"No, it's I that should apologize," she lowered her gaze slightly, "I may have misinterpreted the suitable context for it. I'll—"

"Wait," Add sighed, something telling he would end up regretting this quickly. "I can… help you with that," he mumbled, noticing the way her semblance lightened up almost instantly.

Without another word needed, Add scooted over in his bed, making room for the queen to sit next to him. He stared into her eyes, trying to figure what was going on in her mind — or, rather, core. "Do you… know how to tickle someone?"

"Theoretically, yes," Eve nodded, lowering her gaze to his body. She had already learned that one should look for areas with heightened presence of nerve endings, with it varying from a subject to the other. Narrowing her eyes, Eve reached one to Add's body, holding him by his sides. "Does it tickle?"

"No, not yet," Add sighed, only flinching lightly as the anticipation made his skin tingle. She seemed puzzled and, since he was supposed to assist her in this "research"… "try to move a little," he suggested, holding one of her hands and wiggling his fingers against her palm, then prodding at it lightly and scratching, too. "Like this."

She slowly pulled her hand, looking down at it for a moment. Humans were so unique, after all, to think something like that could be the reason behind so much fuss. "I think I understand," Eve nodded, repeating her actions and holding onto both Add's sides.

…

"H-nghpffft…"

"Does it tickle now?"

"I-it dohoes— ahAh, a bit, yehes," Add giggled, fighting against the urge to slap her hands off his body and push the queen away from him. Why did he even agree to this, he thought, gritting his teeth as he tried to stop the laughter from escaping him.

Oh the other end, Eve was in awe, dazzled. She pressed her fingers against the spots just below his lowest set of ribs, wiggling her digits gently over the thin fabric that covered Add's torso. She was tickling him. After those failed attempts, she was managing to tickle someone. "How much does it tickle? Can you describe the feeling?"

"N-noho!" Add whined, leaning into one of his hands while he grabbed her by the wrist with the other, "ihit's b-bad, juhus- AHAh, wahahait!" He gasped, panicking when she moved her hand, tickling his ribs and the sides of his chest. "Y-yohour mahaj- aghAHAhah, t-thahahat's worse!"

"Refrain from moving, if possible, Add," she asked fondly, a little smile pulling at the corner of her lips when she saw him dropping his head back in a fit of unrestrained laughter, pleading something she didn't quite understand. "I'd like to collect as much data as possible, I think I'm starting to understand why humans do this now…"

A/N: This turned out to be a little longer than it should, but I guess I was craving to write something with them more than I thought

I imagine that Mill flipped the couch over (and themselves) by running straight into it and getting caught, hence the pillows everywhere. (That Eve gracefully let them use before she wrecked them to pieces).

Cc:

Slide 2:

-Eve: Going after my weak spot while I'm asleep? How cruel. You could be a solider yourself if you weren't so obvious. Alright enough teasing, if it's feet tickles you want, than it's feet tickles you're gonna get! Oh dear, isn't that your weak spot too?

Slide 3:

-Eve: Oh man, you're squirming this much and I haven't even touched you yet! Don't worry I'll go easy on you (maybe). Didn't you just get wrecked by my mom a little while ago? I suppose you need another lesson then! Now hold still~

Slide 4:

-Eve: Busting my couch and going after my feet? Be greatful I'm only using 4 vines.

-Mill: Eeek! Ahaha! It was an acci-DEHEHENT

-Eve: Accident or not these feet are paying the fine!

-Mill: Nohoho! Plehehehease!