Well you've been with your "bf" for three months and it doesn't sound like you're that serious about it or him. His best friend doesn't sound like much of a best friend considering what he's doing. Love is a pretty big word to be throwing around like that. You need to be honest with your bf about how you feel and just know that if you decide to break up, the best friends will be no more. I would think this out carefully before jumping into anything.