That must be so tough for you!!! Have you ever stopped to consider WHY you think ur in love with this man? I mean what is it about him? From ur description, he doesn't sound that great. He's cheated on your cousin twice, he's had a child from a previous affair and he's sending you hot and cold signals when he KNOWS ur married with 4 great children!!! What's all that about? It sounds more like he just enjoys messing around. This is just my opinion, but just imagine being in ur cousin's shoes, as his wife, with the feelings u have. Do you think he'll feel the same way about u, or will he just play you like he's been playing his wife?
This is my opinion but i think that you have a great family and you love your cousin.....go to a therapist, talk it out, get over it and then move on with ur family..focus on his crappy points...and compare them to the great points of your family and ask yourself, can i really give this up? i really think u love ur family so be realistic.....that guy sounds like a jerk.....dont give him the satisfaction of messing with you and ur life!!!