Sexual Abuse Support Group
Sexual abuse is a relative cultural term used to describe sexual relations and behavior between two or more parties which are considered criminally and/or morally offensive. Different types of sexual abuse involve: Non-consensual, forced physical sexual behavior such as rape, incest or sexual assault, or psychological forms of abuse, such as verbal sexual behavior or...
I heard about a book called "The Betrayal Bond" about sexual abuse patterns in relationships- it looks really good. Also there is rainn.org that has a database of counselling by local area. There are usually free support groups people can go to at local churces or community centers, so he can even just go and listen and open up when he feels comfortable.
Good luck & you're very wise & good to back him up like this.