This rly be coming out of nowhere but there are 3 possibilities as to why luffy isn’t affected by the love love fruit and has an entirely platonic view of Hancock
1: luffy is demisexual (can’t be sexually attracted to someone he isn’t romantically attracted to) he can’t be asexual because Oda confirmed that he was looking at the women’s bathing area in alabasta with everyone else because he’s just a healthy human boy who has normal human boy desires. This theory being correct would mean luffy is in love with vivi or nami. For this same reason luffy can’t be gay
2: willpower. Bro’s pulling an aijo rentaro and being too much of a gentleman to be fazed by womanly charms
3: anime bs