Hold, bro. They're all under 14. Yes, it should be dealt with, but not in a way
that destroys the boys' lives. Or heaps an unreasonable amount of humiliation upon them.
They live in a society where explicit sex-talk happens ALL the time--so as long as no one's been physically hurt or humiliated, it's probably best that their discipline is relatively light. With ample warning & threat not to let it happen again.
mutu.