It has always been a problem with the tags on this page, let's see, to start ntr is commonly known as netorare which basically consists of cheating on mc (the mc usually does not realize it or does it too late), but they exist 2 other sub-genres of this for which we do not have a tag, which would be netori and netorase, netori happens when it is the mc who cheats on others, that is, he steals the girls (although the netori tag does not exist here the "cheating" is usually used as a replacement) and finally there is the netorase that happens when the MC is aware that others are cheating on him and actively seeks this to happen.
Personally, I don't like netorare and netorase but I like netori, and if I have to be guided by the comments (since I haven't tried this game yet) we have a cheating tag because mc steals the girls and one of ntr since someone could put the horns on us (which apparently is avoidable, I would appreciate if someone would tell me) anyway these things always get confusing depending on who puts the tags