Don't hold your white hairs against yourself- there's only one leader in this room. You. This lad isn't so nice; if he was, he wouldn't be treating your classroom- YOUR classroom, mind- like a bear pit. What kind of school is it? If it's sixth form then he doesn't have to be there. He needs to be aware that if he doesn't toe the line then he can be thrown off the course. SO draw up a list of grievances, arrange a meeting with him and his family, and make sure you get the support of your head of year. There MUST be a sense of consequence for him, otherwise there's no reason for him to amend his behaviour. He probably loves being the biggest fish in a small pond. Remind him you're the angler. Or something. Good luck Tom PS The whole sex thing is just chaff- young men acting older. Inappropriate for the classroom, and tell them that if they do it again they'll be out. Seriously, this kind of stuff has no place in the class.