Sherlock smiled evilly when he heard him hiccup and watched him squirm. Maybe he was starting to doubt himself now.
But it was too late now.

Sherlock played with John's hole a few more times, then the pushed in, hard and fast, opening John up, stretching him past his normal limits. Sherlock didn't let him rest, as soon as he was inside he started at a blistering pace, slamming John up against the stone with every push inside of his willing victim.