Morals are a good thing to have in this day and age. That being said, they don't always apply in this day and age. In a way, I am the same way you are, I would not want to be the one to step between a girl and her relationship with someone else, failing or not, but I've learnt that not following through just might be the biggest mistake that you make. Though keep in mind that, if she if willing to jump boat easily, there's nothing to prevent her from doing it again, and again, whether or not if it's with you.....