I'm lost on what kind of advice to give my friend, anyone have advice to spare? Need help asap!?

Long story short, my friend has issues with control. As in when she gets close to an she completely stops it from happening. She tells me that she doesn't like the feeling of losing control of her body or even thinking about it. She has never experienced an but her fiancee doesn't believe her and is insistent that it has to have something to do with him. When he is trying to get her to that point she stops him and at times he can become very verbally abusive and down right cruel to her about it. The only thing I can think to tell her is to talk to him about it but is there anything else that might help her in this situation? I feel terrible for her and I know her fiancee is not going about things in the right way. Is there something I can tell him to make him better understand? He has come to me about it but not in the way he does with her. Can anyone help at all???