fantasy

So I have a threesome fantasy of me with another woman and a man. I have a boyfriend who I don’t think would be interested in this, and honestly I wouldn’t want to do it with him out of fear of jealousy and things like that. I also have some interest in just being with women more in general. I have experience with women. I would occasionally have sex with a close female friend of mine when we were younger (and drunk LOL). I want to try it sober and with my mind fully functioning. I would love to have my fantasy come true. I wouldn’t do it behind my boyfriends back, but also wouldn’t want to involve him. I wouldn’t want threesomes to be a “regular” thing. Just to explore my fantasy one time. Does this make me a bad girlfriend? Is this an odd fantasy?

EDIT: I have been with my boyfriend for 3 years. i love him very much and we plan to get married. i would want the fantasy to be void of “romance” or “intimate feelings” and just be about fun and pleasure. It would be a sort of one time “exploration” i guess you could say. I would never act on this behind my boyfriends back. and the fantasy is certainly not important enough to me to break up with him over. In that case, i just wouldn’t do anything about the fantasy because my relationship is more important to me.