My Girlfriend Forgot To End Our 'Call',I Later Heard Sound Of Another Guy Banging Her Seriously

I am in a relationship 4yrs on. My girl has cheated on me more than once before she told me about it, promising not to repeat it again. I love her so much desiring to settle down with her, this i told her many times. I assisted her through school inspite of the fact she doesn't allow me touch her as much i wanted to, claiming it's a sin.

Now, she went serving last year in the north, initially everything was fine, later on she started misbehaving. One night in july this year i called her and she told me she needed some sleep, only for her to drop the phone without ending the call, something in me told me not to end the call. After like 5mins, i heard funny sounds and listened the more and it turned out that a guy was banging her seriously all through the night, i even recorded it to make sure i wasn't dreaming. I later confronted her, but she denied it.

When she came back from service in October, she finally told me it was true what i heard the other night, that a fellow corper actually slept with her that night. It really broke my heart as i really loved her and she has cheated many times before and she starves me of sex, saying it's a sin. Now, she says she has changed and won't do it again.

I need some candid advice, will such a woman make a good wife cos am planning on settling down with her next year. Won't she do it again if given the oppurtunity??

pls i need urgent response. thanks.