It never ceased to amaze Sherlock at how John could use being a Demon to his advantage. He had wings to wrap around and horns to hold onto and a tail that was practically prehensile. He could use them all, and they could also be used by Sherlock to his advantage.

Especially the horns. He loved holding onto those.

But this time it was John pressing the advantage, using his tail to his own advantage.

"I'll never stop.." He grunted through his teeth.. "Can't stop.."

Sherlock felt himself building and building until...

"NNNNGGGG!!" He thrust hard again, biting down at his back not to feed but just to hold on while his second orgasm hit him like a freight train He rode it out, thrusting with each pulse of his seed inside of John until he was spend again, panting on his back and still miraculously inside.