I wouldn't call him fuck boy, because he doesn't have sex with different people in the same time frame, he just finds someone he considers beautiful but doesn't know how to love and gets a bit lost in their "relationship" and then moves on, as women were never his priority
Well you just said it beautifully without mentioning the word fuckboy but still what you're trying to say fall into the category of the word Fuckboy.
To me a fuckboy is someone who only has one night stands and doesn't care for their partners feelings and doesn't care about they're well being, which the character is not... He cares about them in his own way, but he's more of a friend, he just can't love the way lovers love each other
I don't like how he ended up being a fuckboy.