Weak: Zelos is a player and flirt to all women because he's an extremely horny straight guy who just wants to bang every female in both worlds.
Woke: Zelos is actually gay, but growing up under such strict religious "guidance" and with the head of the church hating his guts just for the position he's held from birth, he's buried himself so deep inside the closet, using meaningless flirtation with women as an act of rebellion and coping mechanism, that he believes himself to be straight.
Headcanon: ... that is until he's travelling with the very man who, long ago, had made him first discover his interest in men. A certain blue-haired, bisexual, gentleman with boundless charm 😏