Okay, you have to admit there is just something intriguing about a good fuck-or-die. Perhaps it adds a bit of realism to the other wise stretch of reality that is Incest. Either way, Bad Blood brings you that desperation without the underlying want you often see in FoD fics. Neither boys really want to fuck eachother, though Sam does realize it's the logical choice. Dean, however, would rather fuck a horse.
Then all of a sudden it's a whole lot of reluctant reluctance (the very best kind of reluctance!)
All that, and an awkward first time. What more could you ask for?
"Shut up, we've got thirteen minutes, and I am not sucking your dick," Dean said. He gave a heave and managed to pop the head inside.
"Ow!" Sam said. "Dude, payback's in five minutes, maybe you want to slow down."
Dean clenched his jaw and slowed down. It was just—it was disgusting, that's what it was, all that, oh jesus, heat squeezing down on his cock, way too tight, nowhere near slick enough, so it had that little burn of friction going, and Sam under him making little hitching breaths and shivering and giving these little low breathy "oh" noises, glaze of sweat all over his back muscles, so Dean couldn't even brace himself easy without his hands sliding. It was vile. Dean stopped, swallowing air in gulps, trying to get his head back on straight. All right. He was in, he was going to go ahead and do it, get off, and he wasn't going to think about it while he was doing it, not at all, not even a little—
"You're not humming Stairway to Heaven while you do me," Sam said, bucking hard up against him, and Dean said "oh fuck yeah" before he could help himself, and Sam said "whoa" in a kind of strangled way. Dean's hips snapped forward again without him meaning them to, and fuck, oh fuck it was good, it was bliss, Sam panting in time with him, both of them going ragged and whimpering. Dean grabbed Sam's hips, fingers digging in hard to get a grip on his sweaty skin, fucked into him four times and shot like a pistol, all that heat surging up into his cock and out, pulse after pulse, until he felt drained hollow.
And then his hips started to move again, involuntarily, even though it fucking hurt because his cock was too sensitive. He couldn't stop, riding Sam easy now with all his own slick everywhere and still coming, almost sobbing down in his throat. Sam had his head buried down against one arm and his hand gripped on the meat of Dean's thigh like a brand, saying, muffled, "Yeah, yeah," and then he was shuddering all of a sudden underneath Dean, clenching around him and milking him clean.
Dean fell down over him like a cut-string puppet and moaned weakly. "Dude, tell me you didn't just come! You didn't do it yet!"