Derek knows that tone of voice by now, and when Barry's fingertips press into his hips to hold him he nearly shouts for him to stop because it's already so intense. Instead he just sucks in a breath and feels Barry begin to vibrate under his hands, inside of him, and he lets out a sound like a howl. Every nerve ending seems to fire off at once, and the intense ball of heat low in his gut expands until it explodes outwards. His orgasm hits him before he even realizes it's coming, ripped out of him with a force that leaves him whimpering as he streaks Barry's belly with come.

His legs are jelly and his fingers are tipped with claws that leave tiny dots of red on Barry's shoulders, pink lines down his arms, and he sucks in a ragged breath as he clenches down around Barry's cock and does his best to stay upright. "Don't stop-- come on. So fucking good."