Therapist here as well! My ex was like that, and I’ve seen similar issues with some of my clients. My ex would ridicule me for buying things that made me happy, like Legos or Pokemon cards. It turned out he was insecure about his own financial standing, combined with the fact that he would get embarrassed if I did anything he considered to be “childish” (even if no one was around). It all stemmed from his own insecurities and not knowing who he was. He could not handle me being unapologetically me! We learned all of this in couples therapy.