Anal sex, john is too big for Sherlock. Bigger than anticipated and inadequate stretching occurred. John pushing into Sherlock and Sherlock thinks he can take it if only he could just relax a bit more. Only he can't and it becomes too much and Sherlock starts begging john to take it out. Except john doesn't and pushes all the way in. So Sherlock alternated between begging john to go slow and pull out. John eventually orgasms in Sherlock and Sherlock finally relaxed with the relief. John doesn't pull out though, he lets himself stay snug inside Sherlock as his cock softens while he massaged shsrlocks cock and balls into a slow orgasm.

Sherlock cries afterwards.

Much comfort and encouragement from john.