Tell him you won't live in an open marriage. Don't let him use your house to get ready for activities with his OW. He's cake eating big time, and your putting the slices on his plate. Stand up for yourself.
Exactly. I think you argue because you are deeply hurt and frustrated.
Put a stop to this. He got ready at your house beore going to Thanksgiving holiday dinner with HER???! You know how messed up that is? It's disgusting. And he was a pain about having dinner with your own family?
How long do you want to live like this? You are basically telling him it's fine that he runs off to her because you continue to accept and tolerate it.