Comment: It’s called RESPECT! She does NOT respect you, nor your feelings, nor your position in this little 3-way relationship. Walk away as fast as she would if you were still hanging out with a former girl friend. She would (rightly) call you disrespectful, tell all her friends what a jerk you are, and write a weepy letter to an advice column for help to save her dignity. You can be sure she tells him about your bedroom performance.  That's what he's there for.