Ex proposed to the girl he cheated with

Amber • Lvn graduate
Ok I know I shouldn't care but this is bothering me. Found out last night from a friend that my ex decided to propose to the girl that he cheated on me with. Part of me is angry and hurt but part of me wants to just crack up laughing because I know it's not going to work. I don't know if I should confront him about it or just let it go. Any tips or advice?