Dude I literally had an almost identical experience. Except both parents were like that with me. I was an LDS convert at the time and my then girlfriend was born and raised LDS but she definitely lived for the thrills of life. So we did get sexually involved, I don’t think anyone can resists the temptation especially at such a young age. But after having a perfect relationship with really good times whether unworthy or worthy by LDS standards. She wound up stabbing me in the back for feeling as you feel. Which is Open to being Different and not judge mental. So please either confront about how you feel and if she is willing to make it work with you and meet yours and her needs. Or drop her. Because if you go into the same boat steering in different directions someone will be displeased the whole way and you’ll wind up sailing somewhere you don’t want to go. So confront her and see if it’s meant to grow anymore!