I'm not going to skate together with my daughter and my ex at my daughter's birthday party
Why won't you skate with your daughter and ex?
Actually I wanted to show off at the skating rink! I have already told everyone about it too. I just don't want to skate with them.
You should be there for your kids. If you want to show off by yourself, fine. But skate with your daughter and spend time with her.
Sometimes I don't want to be there.
Go and make sure your daughter has a good time. She loves you and you should be there to support her. You don't need to engage with your ex if you have a problem with that.