Aight, I'm just going to mostly gloss over the differences between intentional cheating and netorare (stealing) because I don't feel like getting into a discussion about the nuances of the Japanese alphabet.
In classical Japanese nonsense a man being stolen away from his girl isn't netorare, it's reverse netorare.
A woman being stolen away from her boyfriend is netorare regardless of whether the story is told from the victim or the heroine's perspective. That's well established in doujinshi, but a little more controversial in AVNs where perspective is much more integral to the story telling. For anyone saying that cheating FMC isn't netorare according to this site's tag definitions I suggest you look at this
8 page list of games on this site not following the strict wording of that rule.
The exact same story from the bull's perspective is netori.
Now for my question, are we going to at some point be forced to make decisions for the male victim character? I like FMC NTR but I don't like playing as the male cuck so I'm just asking now for clarity.