The first time Loki discovers just how sensitive Thor’s nipples are, it’s purely accidental. Thor is fucking him, biting a mark onto his neck, and Loki is scrabbling for something to hold onto. His fingers brush against Thor’s nipples and it’s just a brief touch, but it’s enough to have Thor coming with a loud, surprised shout.
Every single time after, however, it is completely on purpose. Thor is all about power and control, and Loki loves to watch and hear him as it quickly disappears. There are few things that make Thor lose his composure quite like this, his breath hitching and his cock immediately hardening. It’s not something that Loki always takes advantage of; he saves it for when Thor doesn’t suspect it, because that’s when he gets the best response.
Like now; they’re in Thor’s bed tonight, Loki seated on Thor’s cock, limbs wrapped around his brother’s body as he’s being steadily fucked. Thor’s fingers are digging into his hips and they’re going to leave bruises, Loki just knows it.
“Harder, Thor, you know that you want to,” Loki urges, his breath hot against Thor’s ear. “You know that we both want it—know that he both want to wake up to find my body marked all over, don’t we?”
Thor groans, thrusting into Loki. “You—you shouldn’t be allowed to say things like that.”
“Then perhaps you should keep going until I can’t speak—until I’m incoherent with pleasure.” Loki’s words are already breathy and it takes a lot of his concentration to keep his tone as even as it is.
The thing with Thor is that he likes to take his time with Loki; he likes to drag it out for as long as possible and while it’s usually enjoyable, Loki isn’t always that patient. Moving one hand away from Thor’s shoulder, Loki slides it between them, until his fingers find Thor’s nipple.
“Loki.” Thor’s nipple is stiff and Loki rubs his thumb over it in small circles, smiling at the way Thor’s fingers dig into his skin just that little bit harder.
“Oh, if you like that, you’re going to love what I want to do to you afterwards,” Loki tells him. His thumbnail is blunt, but when it’s dragged over the sensitive bud underneath, Thor’s entire body jerks. Loki’s index finger strokes it soothingly until Thor stops shaking, and then he pinches.
“Loki!” Thor starts thrusting into him even harder, until Loki is bouncing in his lap. They’re slick and slippery against each other with oil and sweat, and Thor’s grip on him tightens even more, until he’s lifting Loki and then slamming him back down.
“Oh, that’s more like it,” Loki gasps. Both his hands are on Thor’s chest now, tweaking and rubbing and teasing. “Just you wait. Just you wait until we’re done, and I’m going to suck on these until you come all over again. You’d like that, wouldn’t you? You’ll scream for me and jerk with every move of my tongue—you’ll be completely under my control, won’t you, Brother?”
“Loki,” Thor cries desperately, his hand wrapping around Loki’s cock and pumping. “Please.”
“Yes, Thor. Just—oh—just like that—” Loki moans, low and quiet as he comes. He clenches around Thor, smiling at the small, broken sound that this earns him.
Thor is soon to follow, and the moment they’ve pulled apart, Loki is pushing back to lie down on the bed, crawling on top of him. His mouth closes around a nipple and Thor hisses, arching into the contact. He threads his fingers through Loki’s hair, holding him in place, and moans approvingly at the gentle scrape of Loki’s teeth.
Loki’s hand comes up to toy with Thor’s other nipple, pinching it and rolling it until it’s so sensitive that even the light brush of Loki’s thumb over it makes Thor gasp sharply. Then Loki switches to licking that one instead, drinking in the desperate sound that Thor makes.
They’re both hard again and Loki can feel Thor’s erection pressing against his hip.
“Loki,” Thor gasps, his hips bucking as he seeks friction. He lets out a frustrated groan as Loki moves away. “Please.”
“Ah ah,” Loki scolds, scattering kisses across Thor’s collarbone. “I know that you can come from this alone, Thor.”
“You’ll drive me mad.” Thor grabs Loki by the shoulder, pulling him up into a kiss. Loki’s fingers remain on Thor’s chest, teasing him, and Thor moans into their kiss, pulling away just so he can pant against Loki’s lips.
“But you want it,” Loki tells him, pinching harder, until Thor’s nipples are even more flushed. Loki presses another quick kiss to Thor’s lips. “You love it.”
Then he lowers his mouth to Thor’s chest again, sucking and kissing and soothing the pain. Thor’s breath grows shallow, his fingers returning to Loki’s hair. He pulls just hard enough to make Loki moan and they’re both so tense, so desperate to come.
“Loki, please,” Thor begs. “Touch me, please, I need it, I need—”
He doesn’t even finish his sentence before he’s slipping his own hand between their bodies. Loki would protest if not for the fact that Thor pulls him up and wraps a hand around both of their cocks. They rut against each other, Thor’s grip just loose enough for them to slide against each other.
“Yes,” Loki gasps, flicking his thumbs back and forth against Thor’s nipples, grateful for the way this makes Thor pick up his pace.
“Loki, I—” Thor begins.
“Come,” Loki whispers and Thor does, hot streams of it covering them both. Thor wraps his hand around Loki alone, stroking him harder, until he follows with a wordless moan.
“You…” Thor gasps, arms wrapping around Loki, who sags against him. “Loki, you are…”
With a smile, Loki pulls Thor down to lie on the bed. “I know.”
Thor nuzzles against Loki and wraps an arm around him. “Nobody else sees me like this. Nobody else even knows how to reduce me to a mindless mess quite like you do.”
Wrapping an arm around Thor in return, Loki kisses him. “I know.”