I'm into my boyfriend's best friend and I live with them both.
Have you cheated on your boyfriend?
No I'm not, we just really like each other and spent a lot of intimate time together
You shouldn't be interested in your bf's friends. If you want to be in another relationship you should leave your bf.
I don't want to leave my bf.
Then I think you need to just stop liking your bf's friend before things spiral out of control.