Right, and those have different names than "Netorare" but are lumped together under "NTR." Netorare and Netorase = cheating. Also, many of those types of stories start with rape/unwilling, and then they "mind break" and fall for their assaulter, but that's another distinction.
Uh no. Netorase not that different from swinging. It can lead to ntr but, it's not "cheating". It's "cheating" with permission because, the lover gets off on it.
Cheating expresses intent. Intent to betray your lover. Ntr is the act of having a lover stolen. This doesn't have to include cheating because, it can be against the will of the one doing it.
If your lover is raped or drugged or otherwise forced somehow to have sex with someone else. They didn't cheat on you. But, they did get stolen from you. Which leads to all the bad feelings involved with Ntr. Despair, inadequacy, rage, depression, helplessness, etc.
Ntr Type A, B, and, C are just how VNDB helps distinguish different aspects of Ntr for those looking for more specfic scenarios. I just find them convenient and rather appropriate when trying to describe such.
What I described above is Type C. There is no cheating with type C. Type B is what you described which is why I said it's only to an extent. Type A is basically cheating.
Anyway, here's the link to it if ya want.
https://vndb.org/g513
But, for those who don't want to click this exert from it should clear any confusion for this manga's inappropriate use of the term.
3. The trait does not apply if the character having sex with someone else does not have a close loving relationship with the protagonist, and if the protagonist does not experience jealousy and other negative feelings upon finding out about the act. In other words, the ties between the partners and their forcible separation is important to the netorare fetish. For example, an unrequited crush or a potential hero(ine) on a different route would not count for the purposes of this fetish.