If he doesn't interfere in your life, just ignore him.
If he has a certain influence on you, then you just need to keep a certain distance from him.
Worst of all, if he has a great influence on you … er … I think you need to take him very seriously.
In the worst case, there are several solutions:
1. Let him disappear from your life completely, which means either you leave or he leaves. If it were me, I would leave voluntarily because of my personality.
2, don't treat him as a villain, treat him as an adult!
3. Pay more attention to him. The more unhappy he is with you, the more you will appear in front of him. This requires you to have strong self-control and endurance. Theoretically, I think it needs talent. ...
That's all I can think of ... or there is a better way ~ we can discuss it together ~