Well, what I do on situations like that I think on the consequences and maybe I do a pro/con list. But if the things are going bad I think the best is to talk with her, if you leave the things as they are maybe there will be worst consequences and you will end doing things that you must not to do. And with the guy, some people say that if you really love/like the first person, you won’t fall in love with the other person, now question yourself ¿do you really love her?