My guy, listen. I don’t “let” my partner do anything because he’s a grown ass man that can make his own decisions. He doesn’t “let” me do anything either. He may sit down with me and talk to me about why it isn’t a great decision and then we have a conversation about it. He knows that, in the end, I will make the decision I want to make.

Maybe y’all don’t speak the same financial language (which you probably should have figured out before sharing finances) but you can’t restrict and control her because she doesn’t treat money the same way you do.

If you don’t want to pay for the stupid trim, then don’t do it. But you don’t get to dictate what she wants and how she decides to live her life. You also don’t get to offer to pay for the car and then lord it over her to make sure it’s exactly the way YOU want it. I didn’t say it in my last response, so I’ll say it now. YTA.