Well, there's a thin line between cheating and having sex on her own even if she shares the details with the MC later. Since things can't be undone, would it be cheating if he wasn't ok for some reason once he finds out? That's something she can't know beforehand and therefore people could claim that she's cheating in any scene that is out of the MC's radar (I mean, unless they've explicitly agreed on it, like the one with the kids, in case the MC decides to leave knowing what's expected to happen).Right in the OP. Everything that happens is by player choice and with both MC and wife's agreement. I don't see that changing at all in this game. When she is with other men, it's because MC is into it, but there is no humiliation or anything like that. She hasn't cheated in the game and if MC's not present, she shares the details with him. In many scenes, player decides how far things will go, as well.
I can't tell for sure but I think there've been multiple cases like this one, and the more times she does that, the higher she's pushing her luck in this matter. For now the devs have forced us to believe that he was always ok but TBH I don't think things are so simple. From my perspective, that's just an excuse to keep the cheating tag out of the list (many people can't stand the idea of playing the role of a beta).
Regards