Alright so my..............?

Alright my boyfriend wants to have but have me on top riding his .. loll but I don't know how to or anything because usually he is the one on top. loll Like how would I do that [Being on top) BEcause I don't want to emberss myself you know. So can you people please explain to me how to do this? and NO NEGATIVE COMMENTS ! Don't have something nice to say then don't comment this kka :) OH AND I KNOW THIS IS UNDER THE WRONG CATEGORY .