That can be good too, i like the whole betray your partner behind his back, in fact the only instance of ntr i usually dislike is cuckold, where the guy is not only willing but fully aware.
There's also some optional events that play on sort of the same feelings as NTR. one where the heroine becomes trapped underground with a man who loves her and another man who just wants to hurt the other man and steal her. You have to dig around the area to find the way out with limited stamina, each time you run out of stamina a day passes and events occur with failing to find the way out by day 9 or 10 ending in a bad end.