Boyfriend

I love my boyfriend. We have been together for over a year. But lately I have been feeling weird about our relationship. We are very comfortable with each other. Almost to comfortable to the point where I feel like we are an old married couple and I feel constantly annoyed with him. I am twenty and he is twenty four. I feel like we don't have a lovey dovey phase and never really had that phase past our first month of dating. We talk about our future together and he wants to get married. I haven't had many boyfriends and I feel so comfortable with him that I can tell him anything. I don't want to start over with someone else. I just feel like our passion is gone sometimes. We don't really kiss and when we try to have intercourse I feel like it isn't romantic. I don't want to loose him but I'm confused on why I feel this way. I feel like he is missing our love connection? or maybe it's me? I don't feel the passion like I used too but at the same time I love him and can see a future? Advice?