One more under the radar...

Considering what the OP states,
how organic are we talking about? Does the faithful path exclude any and all ntr/swiging or does it still allow for consensual sharing? Someone said in the thread that cheating with the mistress makes the MC "selfish", looking for a personal advantage; can he or the FMC have sex with others for mutual advantage (for example) while on the loyalty path? Or is all NTR by the FMC locked in a bad route, requiring the MC to cheat and be caught cheating? Or maybe there's redemption in that route (that would be too good, wouldn't it LOL)?