I'm not a fan of NTR and I don't understand all this explosive rhetoric in response.
- The MC and his roomsismate are not a couple - nor does she show any intent on being in that kind of relationship with him - when the scene pops up about Darnel having her show her pantied butt to the MC.
- The MC and his landmomlord are not a couple - in fact, the MC is drugging the landmomlord into doing his bidding - when the possible scenario comes into play with Darnel and her at the gym.
Without either being a couple the basic accepted definition of NTR is not met. Just having the MC's love interest (when there is no consensual reciprocating interest, feelings, and/or actions) end up in a sexual situation or a relationship with someone who isn't the MC doesn't rise to the level of NTR regarding the MC.
One might even say since the MC is possessed and many of his thoughts are manipulated by the possession that he, himself, isn't a consensual partner in many of the activities he's partaken in the game.
Was there this much contention when Becca was being sexually harassed in the gymnasium before she and the MC were an item? I don't remember. But again, it was when they were simply friends and before they were a couple.
[Bracing for the coming storm]