Virginity

My goal is to not have sex until I'm married, but the guy I'm with says that it won't be a big deal if we don't wait. Also, I do really want to do it with him, I just don't know if I should let go of my goal and do what makes me happy, or stick with my goal and waste a bunch of time.. Thoughts? (Also side note: I'm also worried about what my mother would say because it would kill me to keep it from her, seeing as I'm very open with her about everything)