I said this to Timmy Reed (developing an overhaul mod for "That Girl") i will say it to you as well...
Having the wife's cheating be linked to MC cheating may not be a good idea in the long run and will only limit your own creative freedom, if the two variables are separate you will have room for a lot more variation and i'm not just saying this for ntr but for all variables. you shouldn't lock yourself into something, specially this early on...
As for the ntr specifically, i recommend changing to wife's pov so the player can decide.
GOOD LUCK with the new project