@degenerateafro Yeah no, he's not a cuck, just a beta buck soyboy (got an actual explanation in a bit).
Doesn't have to be a wife, but it's supposed to be an exclusive relationship deal, you get the idea. And yeah, the women aren't sleeping around so I don't get it either.
The thing is, these beta MC's that are wishy-washy, indecisive, doesn't want to get involved/be a hero etc, are the older version of anti-heroes.
When most people think of anti-heroes, they think of guys like The Punisher; vigilantes, does atrocious acts and can hardly be called a hero, if it weren't for his or her enemies are worse.
But waaaay back when, anti-heroes were simply the opposite of a classic hero; where a classic hero is brave, the anti-hero is a coward, where the hero is decisive, the anti-hero cant decide on their fucking breakfast, etc.
Japan likes these kinds of anti-heroes. But they use them in harem and romcom genres because it lets the audience claim a harem member or the MC's SO as their "waifu". Or so I'm assuming.