As a victim of rape/incest myself let me offer you some advice. I was a victim of my father from age 15 to age 22, resulting in the birth of 3 children. I was hospitalized, beaten, well let's just say it was the most traumatic experience of my life, and I have 3 daily reminders for the rest of my life. I understand your concern, but there is a lot of shame, guilt and blame to deal with. As beneficial as it will be for him to talk about it, you need to let him come to you. That will take time. He has to know that he can trust you whole heartedly, before he'll be willing to share. AND most importantly, if he does come to you, don't bombard him with questions. It's an incredible long healing process, and it requires much, support and understanding. You might be surprised to find he probably knows that you suspect. The more you talk to him, the more he may open up. When, and only when he's ready can you offer him the help and support that he needs. Your best bet is to get a hold of a rape/crisis center or R.A.I.N.N (Rape, Abuse, incest national network) and speak to a councellor. www.rainn.org
I am now 31 years old, I am a stay at home mom who is happily married. My husband is well aware of my situation, and I don't think I could have made it through all of this with out him. I was lucky to be able to find some closure for a short time, as I had my dad charge and he was jailed. Now I have to worry about the fact that he is due to be released this year and the 14 year old daughter that we share could be his next target.
This is a tough one, I am inclined to say to you "run a mile" running several relationships doesnt bode well for you having any future with hiim if you are hoping for that. The only way he can be helped really if he was abused is by counseling/Therapy he has to want to seek help you cant do it for him ,the only way would be to have a talk with him and tell him you care and that you feel he could use some help..You need to look after yourself I think you will only have heartache if you take this on, you can however advise and let him choose to take that advice or not..Good Luck