Help. I think my boyfriend is happier with my female roommate than with me.

So my boyfriend and I live together. We have a female apartment mate. We've all become close friends in the past year. However, my boyfriend talks more with her than with me. It seems like they are a couple. The thought that maybe they are dating has crossed my mind but I don't think so. I don't think my female friend would do that to me.I just don't know. I feel like my boyfriend isn't even paying attention to me. He would rather spend time with her than me. He honestly looks more happy with her than me.