.
Unless you look like a 12 year old shota boy in real life there is no self-insertion as the MC here. and people cheat all the time IRL but its usually not with a fat ugly piece of shit lol.
I like the NTR stories that feel like they could actually happen those are usually the ones that inspire the pit of your stomach awful feeling that can be fun to explore sometimes. Like when its a normal joe MC in a normal relationship and you still get cheated on despite doing everything "right"? That's some heavy shit. This fag MC deserves it though even though it doesn't mean anything cause it's not like this antagonists is much better or could even steal a girl away from anyone other than this Shota MC.
Here's the thing, not everyone self inserts themselves into these stories. I know I personally don't. Also, you don't have to look like someone or something to self insert or people like, you know those of us of the darker skin variety can never self insert because 90% of porn games Mc are always either white or Japanese. Even when they are nonhuman, they take human forms that look white or Japanese.
So self insertion based on appearance already is a fallacy.
With that said, I don't even understand how someone can self insert into a ntr at all, you either have to be a victim, a idiot, or an asshole. the one being cucked always make stupid choices and decisions even when obvious common sense choices that would play in their favor are right in front of them
The one being blackmailed or cheating always do stupid things. "Oh no you recorded me sucking your dick? You promise to delete it if I let you fuck me...in a place of your choosing at a time of your choosing giving you ample time to set up cameras that you'll use to keep blackmailing me? While I ignore the fact I was literally drugged and raped and don't want to go to the police because stupid or some how it's my fault."
And than the asshole. He's probably the easiest to self insert in because he's the one having all the fun.