Bisexuality in a relationship

Okay so I'm bisexual (have been ever since I've known myself) and I'm currently with a boy for over a year now, and never been with a girl, but it interest me a lot and I wanna try it out. I have discussed this with my bf but I always end up saying "no you're the one I need" and "I don't need girls" because he'd feel he's not good enough but he is it's just I'm kinda more into girls? Idk but I don't know what to do😭