Ahah, I like the fact that girls are not in love with MC (cause of his magical dick or "Just because"), they all Just potential fuck-buddies at most in my opinion, and tbh I feel even less emotionally involved with them, and don't really see why MC must feel anything for that women... and if he feels, I won't believe, there is totally nothing "in the air"
So I'd stay totally friendzoned/professional with "his old crush", "nerd collegue", "Ice Princess", "the Dean" and... (at maximum) fwb with "junky girl". Side girls are fwb anyway.
But I know it'll be boring like hell((
No offence ofc, I wish dev luck. Slowburn is always a better alternative)