Why do you have a problem with your Dad finding someone & getting married. IMO, it proves that he had a good marriage to your mom or he wouldn't allow himself to have feelings for a new wife. Trusting that this marriage will make him as happy as his previous marriage.

Men also like to have someone there to take care of their home & make it less lonely.....where many times women are more independent after the loss or divorce from a husband...especially if they felt the marriage wasn't the greatest.

Radical acceptance is a DBT term.....it basically means that your Dad is remarried....you may not like it or the woman he married, but there isn't anything you can change about it....it is what it is.....so why make yourself miserable...because you are only making YOU miserable & accepting it without judging it good or bad is what you need to do.

What good is making yourself miserable doing for you?.....what are you getting out of the feeling.....hoping that it will make your Dad feel miserable for doing what he did.....its done.....he wouldn't have gotten remarried if he didn't believe that it was the right thing to do & that THEY were going to be happily married.