Why doesnt she like my boyfriend?

My best friend is really annoyed with me because I have a boy friend. I wasnt expecting to date this year because relationships can be dramatic, expecially in high school. I dont talk about him a whole lot and I spend more time with her than my boyfriend, and I havent blown her off. It is really frustrating because she cant accept that Im happy, and she brings up my boyfriend and when answer her all she says is "Oh, thats cute?" What can I do to solve our problem?