Cheating is different from NTR and cucking, but NTR and cucking are generally one and the same thing. The problem is that the definition has not only become muddied in recent years, but has largely, and wrongly, changed in the eyes of many people because a bunch of whiny, incel, man-babies kept crying "NTR!" every time a female character in hentai, adult VNs, etc, was seen doing anything romantic or sexual with a character that wasn't the MC, even if that female character wasn't even a LI.
And even if the female character was a LI, it was very rarely the case that they were fucking some guy in front of the MC and making him suffer, and it was more about simply advancing the plot by seeing her hold hands, kiss, and do other light things with another character in order to make the protagonist work harder to win her over.
But all these beta, incel, keyboard warriors cried and whined so much about seeing their waifus even look at another guy that they've successfully bamboozled enough people into thinking that NTR is any and all types of romantic/sexual interaction with a character that isn't the MC, as opposed to what it actually is and always was; a male MC seeing his LI with someone else and having it rubbed in his face in a torturous way, moreso if the LI is enjoying it too.
Ergo, this game has no NTR, it's just cheating.