It had taken some time for Finn to learn how to take. It's a good thing Poe is such a giving person.
And, okay, maybe his reasons hadn't been entirely altruistic, but Poe is so far beyond caring, shame, anything. He's reduced to a thing that needs Finn.
He had started out on his hands and knees, but it hadn't taken much to make him so loose-limbed and blissed-out he can barely support himself. His thighs are spread wide, hips canted into the way Finn's fucking into him. One of Finn's hands is pressed firmly between Poe's shoulder-blades, pushing his chest into the mattress. The other one has a steady grip on both of Poe's wrists, and Poe might feel embarrassed at how fucking hot he finds that if his brain didn't feel like quicksilver, sparking with liquid pleasure.
Finn is a wall of firm muscle against his back. Poe doesn't have any leverage, couldn't move if he wanted to. (He doesn't, except maybe to press back harder into Finn's hands, into his cock, so he could still feel this tomorrow.)
"Fuck, you're so-" Finn breathes into his ear, distracting himself with a particularly sharp snap of his hips. Poe can't respond with anything more than a wanton moan, one that almost certainly carries through the thin metal walls of his quarters.
His entire body feels keyed-up, nerves singing at every time Finn's strong thighs press into his. The stretch and slide of Finn's dick inside him is slick and sweet, so good he can barely take it. It's like throwing his bird into a tight Immelmann turn, riding the engine at the verge of stalling.
Finn adjusts his angle and Poe's brain whites out for a second. His body tries to twist into the movement, but Finn holds him firmly in place. He can vaguely hear himself making sounds that are closer to sobs than anything, but he's too busy having his world rocked to have any dignity.
Suddenly the world lurches, and Poe finds himself hauled up and backwards. He's standing on his knees, now, leaning back against Finn. He's ever-so-slightly off-balance. Finn's arms are the only thing keeping him from falling forwards, pulling him back even as his hips jerk him forward with every thrust.
One of Finn's arms is wrapped proprietorially around his waist and up to Poe's chest, where his wrists are still clasped together in one hand.
Poe groans and lets his head fall back against Finn's shoulder. He tries to press a kiss into the soft skin of his neck, but mostly he just ends up breathing loudly and messily against it.
"That's it, sweetheart," Finn mutters, and brings his free hand to wrap gently against Poe's throat. There's no pressure - there's barely any weight, but the casual possessiveness of it kicks Poe over the edge.
It's overwhelming and a little chaotic, like pushing a little too hard into an aileron roll, but so so good for exactly the same reasons. Finn keeps fucking him through it, slow and deep. Poe lets himself drift and go boneless, because he knows Finn will be there to take care of him. He's vaguely aware that he's grinning.
"You're so beautiful, how did I get this lucky," Finn's saying, but it sounds rhetorical so Poe doesn't do anything but hum happily against Finn's neck.
Finn's thrusts get a little erratic at that, and soon Poe feels him come with a shudder and a bit-off curse.
Finn guides him down onto the bed so they're on their sides facing each other.
"Okay?" he asks, running a hand up and down the lenght of Poe's side.
"Extremely." Poe feels a little giddy and out of it in that perfect, fucked-out way.
"Good," Finn says, and smiles brighter than any star Poe's ever seen. "Let's get you cleaned up, okay."
"Mm. I'm going to pass out now," Poe replies, and drifts off to the familiar sound of Finn's laughter.