Here's my story..midlife crisis/infidelity

[January girl]

I had quite the shi**y weekend. AGAIN, I lost my cool and said WAY more than I should. Friday night he went out with a guy friend of ours and stayed out until 4:30 am. Saturday night he went out (I'm sure to see her) after we got home from a dinner we had to go to at 11:30 pm. I was quite a whiney complainer when he said he was going out on Saturday. I'm trying so hard to detach and it's just not taking on every day. Some days I'm pretty good...others, not so much. I told him I was tired of all the crazy hours and inconsiderate ways of him. After he left I thought about taking our kids and leaving....but this is my home. He should be the one leaving. On Sunday I told him that I know he's sleeping with her and how did he feel in the past "cheating" on his mistress with his wife? "Guilty" he said. (We are not longer "sleeping together" once I found out he was having sex with her I could no longer "be" with him....yuk!...just saying.)

Anyway, here is my question of the day....
He wants to move out and I believe that I want him to move out
SO

Should I give him the money to have first month's rent and security deposit just to get him out of the house because his hours and ways are making me crazy?
Or should I work harder at detaching and possibly wait this out? He has been involved with the OW since July 2009 first EA and then PA as of September 2009-my best estimation.

He says that she is his perfect match. He dated her in high school- 7 years before we started going out. Her family is a train wreck, her finances are a mess, she has a 16 year old son with a man she never married, she is also having job troubles, she loves to drink and party but "has a beautiful singing voice" ...which is a hobby they both share.

He and I have two children together-D9 and S1.