Plenty of women fall for playboy tricks irl though. There are literally documented methods of gradually introducing women to prostitution, that include such playboy tricks. Most of the times it's exaggerated in these ntr stories, especially with dumb blackmail shit, but it does happen.
What is completely unrealistic, is the way their male partners are being portrayed in these stories. They either have to be braindead, not seeing what is literally happening in front of their eyes, or magically turn into willing cucks with no prior indication of that. Or both. Cheating irl involves a lot of anger, confrontation, guilt/desperate apologies and often times depression. Ntr stories skip everything but the latter.