idk, his feelings make sense to me in a vacuum but he did deal with Hanabi and the ex, girls similar to this bitch now (legit can't care to remember her name). This is conveniently dumbing him down bullshit.
Him going "yeah, whatever, it does absolutely include the girl I like but I have no right so whatever" while knowing that the bitch can ruin their relationship is dumb. He is being an asshole for keeping her advances secret and letting his "friend" be around a clearly bad influence. He knows all that. Factually.