- Netorare: Unwilling cuck [mood click]
- Netorase: Willing cuck [never click]
- Netori: MC does the cucking [always click]
The issue is that in all three scenarios the women is also involved with someone else, so in all three scenarios you are being cucked as the the 'side piece'.
i.e. if you change the narrative slightly - a game focuses on a female, she goes and seduced a married man. That man is still married and banging his wife. You are still the side piece.
So as the primary focus of a game its not really that popular (people into that jump into NTR wholesale), however within games it is an extremely common occurrence and there are many many games where it exists. However its incidental, i.e. 'meet character A, would you like to romance character A. Character B is the sister of Character A, and is married. Would you like to romance character B. Or would you like to romance A & B.'
basically its everywhere in games just not the primary focus of games.
Another thing I noticed is that not many netori games(male protagonist games in general) don't have ugly bastard for a protagonist, but they are present in NTR. Male players obviously prefer to see MC's girlfriend/wife be taken by ugly bastards instead to be.
I think its more that games with a 'good looking' MC are more of the power fantasy game where you are the bestest most handsome most charismatic on earth and cannot be resisted. Ugly can be either the 'other' power fantasy where ugly= bad person, or It might just be 'i cant be bothered to put work into this character because im wanting to look at the other things'. Rarely are the ugly characters drawn/modelled extremely well, they are usually minimalist.