Hi there.
First, take a deep breath. We have very little information about children's sexuality, so schools (and everyone else) tend to panic when any child shows an interest in sex. We don't know why your son is asking girls to have sex--since he really doesn't know what it means. It may just be that he's being provocative for a reason and has found something that pushes adults' buttons. Or it may be something else. It's doubtful he actually wants to interact sexually with them; however, most people are woefully unequipped to help kids in this arena--including the counselor you sent him to.
It's doubtful your pediatrician will know a sexologist who can help you and your son, but, of course, it never hurts to ask. However, realize that an untrained, unskilled, judgmental person can do more harm than good.
Send me a private message with your location, and I'll refer you to a qualified professional. Dr. J
take your son with u to your gp, have a talk about it and they will reffer u to the right person for him, his problem does need to be delt with by a consistant person and i hope it all works out ok for him