I don't know what happened to him to not want to fall in love (most likely got betrayed) but he's just making the same mistake that happened to him. Reap what you sow.
I'm so happy that the anime is explaining the relationship between Asta and co and Fanzell and co (when Nozelle and Fen try to find a way to cure Asta's arm). I remember being so confused when they introduced those characters and didn't explain anything about them
Why must these men keep running away from their issues!! Only Yoon (mc) is facing things alone