He's probably aromantic, like he doesn't really experience romantic feelings for anyone in general. Physical attraction yes but romantic attraction not really or not at all.
So he probably believes he can't love him back so he's being honnest with him out of respect and for the sake of simplicity, he's a << non-stick pan >> and not a << velcro guy >> lol so he's being upfront about it to un-stuck himself from entanglement with another person's feelings he knows fully well he can't reciproquate, and un-tangle from a situation/relationship dynamic that's simply not right for him ... But then :-) maybe love is not only about romantic feelings :-) maybe there is other type of feelings that can lead to love and/or the desire to date someone. ?? I think i like this story !! :-) it feels quite realistic i think.
It's only getting started. In chapter 7 we see he might want to be closer to him .. :-) for other reasons than '' romantic desires '' but still he's interested. ! He likes him in his own way. We'll see if that will turn into a desire to commit into a long term relationship or not. It's an unusual dynamic that's why i like it !
He is so cruel to say while smiling that he doesn't love him !!!! Though he does