My instincts are to be super cynical about thsi guy because his behavior is nuts. But.... it’s like he just loves her so much and has no idea how that’s supposed to be done
People seem to not understand that he is a yandere because of his unrequited love for FL.
Yandere trope love is obsessive and toxic if you don't reciprocate. The character will either give you the whole world or destroy it with you included.
This is fiction so don't take it to heart and a lot of ML are like him if you pay attention