NTR is just one fetish among many. It's not uncommon for fans of him, including myself, to like a lot of other stuff as well. This is partly because pure NTR doesn't work on its own. Games that are actually only aimed at NTR, that contain nothing else, are almost always garbage.
Easy telling: It needs a vanilla foundation to get into the story, where NTR adds the spice as additional content. You can't steal anyone from a relationship that doesn't exist—that is, if there's no husband, boyfriend, or anything like that. And the cuckold fetish doesn't work without the cuck.
For example, I'm a huge NTR fan, and generally all kinds of taboo stuff. But I also play games like BaDik, everything from NTL Media (ToN, etc.), so stuff that really has nothing to do with NTR. My real fetish are good stories. And I'm not the only one.