[Showme_urmove]

Why are you mad about the things she did in the past. You and her didn't date, no strings attached, so what's the problem? Lets just say, even if she had sex with that guy, you have no right to be mad, cause you and her were not together!
Why fight and waist all your time for something that you can't control. Its one thing she did something with that guy while you were with her, then yea I can see you having the right to know, and be like a detective and interrogate her, but all was done while you weren't even together.

If she brought up the past that's her, teach her, show her the correct way of having a healthy relationship. Believe me your relationship with her would last longer then others. Fight and argue on something that's worth doing. Like if you both did something wrong while you were together.
Go and set down with her and just let tell her.
"Babe the past is the past, we can't change it, but we can change the future. Whatever you and i did in the past, we werent together, so their is nothing to be mad about. Lets move pass this and built our relationship on the future, not not worry about the past".

[Kitkat22]

You all will work it out. Be thankful you have each other.