The protagonist has always been an asshole eversince he became a playboy, so no surprise on that.
Yeah, I agree with you on that, I suppose that little flashback just really came off as incredibly harsh to me though. Especially reading between the lines on what I personally believe the author was showing in that scene. We know from his thoughts and memories that he'd entered into a loveless (read nothing but sex) relationship with that girl in his "real" past.........essentially preying on her feelings for him to take advantage of her and bang her whenever he felt like. So basically what we saw in his memory was him just getting done having sex with her while her parents weren't home on Valentine's Day and then spurning her gift as he walked out the door without another thought. I honestly can't imagine anything harsher.