You're making out with Karkat in his room, semi-recumbent on a pile of knitting scraps (courtesy of your sister and her girlfriend) when he brings it up, or at least tries to.
"Mmh, Dave," he mutters against your lips.
"Yeah," you breathe, pulling him back into the kiss. You nibble gently on his lower lip before running your tongue over it, and he groans.
Honestly it still surprises you just how into kissing Karkat is. His lips part as his hands tangle in your hair, and you take the moment to appreciate the weight of him in your lap, his chest flush against yours, your arms snaked around his waist; sometimes you think he feels so very small, and you wish you could envelop him completely. You push into his mouth, run your tongue against his, along his teeth, across the roof of his mouth. He moans into you, but instead of pushing deeper he pulls back a bit.
"Dave," he tries again, pushing off of your chest. You sigh and lean your head back. Why does he have to want to talk now? You were enjoying getting your mack on with your best bro, and now he's ruining it.
"What?"
"I wanted to… ask you about something."
"Do we have to do this now?" You want to hear what he has to say, you really do, but god dammit you're a teenager and you were just making out and you really, really want to keep doing that right now.
"Ugh." Karkat rolls his eyes and resumes kissing you; you smile against his lips and hum contentedly. You know he doesn't want to stop either, that he's just making a show of being upset because he's a drama queen and that's what he does.
This time he takes charge, pushing his tongue past your teeth. It's slightly longer and more flexible than a human tongue, you think, but you're not certain because the only human tongue you've had in your mouth is your own. Regardless, you love the way his tongue can curl around your own, reach all corners of your mouth, make your head spin.
You used to think kissing was pretty gross, what with how dirty mouths can be. But at this point you really can't complain, especially considering where your mouth has been in the recent past.
(You won't tell anyone that you've been spending more time on your dental hygiene since you've started this thing with Karkat.)
He leans into you, seemingly desperate to meld his abdomen with yours, and you gasp at the increased contact. He just moans into your mouth, sending a jolt of excitement through your body and towards your crotch. Suddenly he pulls away from your lips and migrates to your neck, causing you to shudder as he pecks and nips gently at the skin.
"Mm, what're you—"
You're cut off by his fingers sneaking under the hem of your shirt and his hands—so warm, everything about him is warm—press against your abs. He grinds down into your lap and oh god, shit, okay, you're really fucking turned on right now. You're starting to get lightheaded from all the blood rushing to your dick, and then Karkat sucks on your neck, and you moan. Loudly.
"Shit, Karkat!"
"Dave," he coos as he soothes the spot with his tongue. You're trembling now, and you're worried that if he keeps this up, keeps caressing your torso with his too-warm hands and marking up your neck with his too-wet mouth, you might come in your pants right the fuck now, and that is the absolute least cool thing anyone could ever do.
"Karkat," you whisper breathlessly, pulling him off your neck, "Karkat, fuck, stop, I can't—"
And then he fixes you with the sexiest look you've seen on anyone ever, and god, you'll let him do anything to you. He mutters your name again as he pushes your shirt off, and you're literally shaking with the effort of staying put. Then he's kissing down your sternum, down your abs, past your navel, stopping when he reaches the waist of your pants and you whimper, knotting your fingers in his hair.
"Karkat, please," you pant, and he nuzzles against your crotch. "Fuck! Jesus shit just do it already!" He complies, tugging your pants and boxers off in one go and you cry out as his warm breath hits your bare erection.
You absolutely cannot believe this is happening right now. You've fucking dreamed of shit like this, you've jerked it to the mental image of Karkat with his lips around your cock, and now that it's actually happening you can't get your brain to slow down enough to appreciate it.
A weird breathy noise escapes your mouth as Karkat tentatively tongues the head of your dick, and your hips buck involuntarily. He holds you down with one hand and strokes the base with the other before taking the first couple of inches into his mouth. You immediately bring a fist to your mouth and bite down, choking back a moan; it's all you can do not to come right then and there.
Then he takes in just a little more, humming against you and sending vibrations straight through your dick, and you fucking scream into your hand. You can't believe he's reduced you to such a blubbering mess when he starts to move, bobbing his head and sucking and then he pulls off and he's licking the underside of your cock, trailing a wet kiss from base to tip and it's so much, too much.
"Fuck, Karkat, yes, oh god, oh my god fuck yes, yes!" and you come shuddering onto your stomach, just barely missing his face, as a long wavering moan curls out of your throat.
All your muscles have turned to jelly, and you melt into the knit pile. For a few sweet seconds, your mind is utterly blank as your ragged breathing evens out and you come down from your high. As soon as you do, Karkat is back to kissing you, and you realize that he must be desperate for some relief but you also remember that he wanted to ask you about something, so you twist your head out from under his and gather your bearings.
"So what was it you wanted to ask me about?"
"You fucking asshole," he snarls, rutting against your leg, but there's more arousal than anger behind the words. You snicker as he grips your shoulders desperately and you run your fingers through his hair. "I wanted to know if…" He can't seem to finish the thought, and you can feel his bulge pressing against your hip.
"If what?" you ask, tucking a lock of hair behind his ear.
"Fucking– god dammit, I want you to fuck me!"
You blink. Oh.
"Oh."
Oh.
You weren't really expecting to hear that, but you can't say you're opposed to the idea. You get that it's kind of a Big Fucking Deal, though, so you were careful never to bring it up, outside of your joking offer the first time you two got together. But Karkat is asking you, and that's all you need to hear. This is where being a perpetually-horny teenager is a definite benefit; at this rate, you can probably get it back up in a few minutes and be ready for round two (for you, at least; for Karkat it'll still be round one).
Your only concern, though, is whether it's even feasible. Are nooks compatible with human junk? What if you hurt him? You know that if you did Karkat wouldn't hesitate to punch you in the face, but still. It's a risk you're not sure you want to take.
"Are you sure? I mean, will it work? I don't wanna hurt you, dude, we don't have to do this, really, it's okay if you change your mind, shit bro—" and now nervousness has taken over and you can't seem to stop talking.
"Would you shut your fucking wind hole for one god damn second?" You decide for once to do the smart thing and shut your trap. "I'm… I want to try it, okay? I don't know if it'll work and I've never done this before and I'm kind of freaking out but I think we should give it a shot." You can hear him fighting to keep the fear out of his voice, so you pull his head against your chest and stroke his back comfortingly.
"Shh, okay, we'll try it, but you have to tell me if anything feels wrong, alright?"
"Yeah," he whispers half into your skin. "Alright."
