but d didn't do much/anything with frank.
Netori describes when the lead steals someone from another - kind of reverse ntr from the player POV. Even though Frank never did it with D, they were technically in a relationship to make it netori.
Actually, there is stealing the affections of people is several instances:
- MC steals D from Frank.
- Rachel steals Frank from D (ostensibly).
Then there is cheating without stealing the partner which I don’t personally call NTR, but that’s my opinion:
- MC with a bunch of people
- D with Elena
- Rachel with Frank against Brad
Then there is swinging where both partners agree and are willing:
- Graham and Olivia and MC
Finally, there is the stealing of affections of D from Rachel - not really ntr, but something deeper.