You really don't know what the words you are using mean do youno, [cheating] means betrayal. ntr means EVERYTHING. which is the problem in this forum for a long time.
besides, implied sex is also ntr, because part of the ntr is people fucking behind your back. besides, like i pointed earlier, one of the love interests is implied to be in a gangbang, which would constitute ntr by your own definition.
Cheating aka adultery = NTR (aka fucking behind your back)
Consensual sharing is not,
I'm not continuing this, this has be argued to death, use google if you want to educate yourself.