Like laBug said, don't do anything based on emotion right now. It sounds like you just started showing him you weren't going to keep the status quo. I think you need to give it time to sink in. It seems like he thought he was going to be able to keep the OW and have you and the family.
It also sounds like life is not so great with OW either. It doesn't sound like OW wants this 3some either and she doesn't like it when he spends any time with family. He isn't going to like that.
M 48 H 50 M 25 T 27 D 20,18,15 6/11 H filed 3/12 H dropped 4/12 H moved out