Sadly more kids know about *** than I did at that age,they will often see a picture of people being naked from their friends or any of their older relatives.It's better to expose him to it when he's ready than to have him get all awkward when seeing tits for the first time.later rather than sooner. he's 7, hes going through that 'eww kissing disgusting' phase. he doesnt need to see some ass; besides he'll probably tell my parents, **** that.