Is it normal husband admits affair leaves with no contact then smugly returns?

My husband told me he had been trying to have an affair with a woman 40 years his junior at work. He told me because we were going through counseling and he was trying to come clean with all of his cheating behaviors (which were frequent). He is 61, she is 26.

I put 2 and 2 together and realized everytime he worked with this young woman, he would ignore me for days, wouldn't talk to me, let alone sleep with me. And the entire time he was chasing her (over a year), he was extremely distant toward me, and became disrespectful. He admitted he thought he had a chance with her for a long term relationship.

He told me this right before we were to go on a long trip to meet friends and family.

I put down my foot and told him I wanted a divorce. He left on the trip for a month, and did not contact me once. He has a "harem" of women friends he can talk to and visit, and with his history of infidelity and flirtatious behavior I can only imagine what happened.

Now he's back. He wrote me a short email that said, contact me if you want to start a "new" relationship with him.

is it normal that I have given up on him? Should I forgive him and continue counseling? I feel like he pushed me off a cliff, shrugged his shoulders and walked away.

I can't do it anymore for my sanity. Every time we go out now, I look at young women as if they are the enemy. and I like young woman! I don't want to behave this way. Help!!!