I have to ask "what was your game with him?" You knew he had a girlfriend yet you allowed him to act inappropriately with you then and even now that she is pregnant and he has chosen to be with her (in a rather dysfunctional "together" but none the less, still together with HER).
You would do well to stop all contact with him so that you can get over the addiction to having his attention, but never having him.
You're over-stepping boundaries with this bullshit little "game" you keep perpetuating by allowing him to disrespect both you and the mother of his child.
Move on and stop the nonsense. You'll never find your own boyfriend while you entertain his fluff.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion