I completely understand you when you say about not having contact with ex bf and gf. I am not secure enough to deal with that at all, especially in a new relationship. I believe that a person's past makes them what they are today. If I ever found out that my bf had treated a woman poorly in the past then it may be a deal breaker for me. Look, she has had this on and off again relationship with this guy. She obviously has feelings for him. Talk to her and let he know your concerns.