I have been with my girlfriend for a little over 2 years, and we live together. Sometimes I am just not in the mood to fuck her. I'm not saying that I never am, but sometimes I do it just because she wants to and it's boring. She is very good to me and I think I would miss her if she were gone, but I'm afraid to think of what my sex life would be like if we got married. Is this normal or should I think about moving on?