I 1000% feel your pain. About 6 months ago I asked my fiance of 9 years to move out. He is already living with someone and it breaks my heart--and we are still on good speaking terms. In fact he fixed my car today and she was there. Ouch. Hard hard hard. I think it hurts too because of the time spent together. Memories are hurtful things sometimes--even the good ones. You have a son together--there were good times; and now her bf is staying there it hurts, whether you still want her or not. History. That's why it hurts. Lenny's idea is great. Find something to really really occupy yourself. Good luck.