I feel like there's still a general majority of degenerate English-vocabulary-knowledge of people who still don't know the general meaning of the word/ term of "NTR". Very briefly --
- Neto-RASE, basically means very similar to prostitution, the person essentially agrees to sell his/ herself for money. There's often an expression of regret for it though such as feeling guilty. But mostly the regret or remorse for this is seemingly absent in most depictions of it that I've seen.
- Neto-RI, basically a slow or quick meaning for "Reluctant but Willing", where essentially the Significant Other is aware that their partner is off fucking or getting fucked by other partners. (THIS is where you'd be more correct to call it "Cuckolding")
- Neto-RARE, is literally the Significant Other (I'll abbreviate this as "SO" from now on), is COMPLETELY UNAWARE that their boyfriend/ girlfriend have been "Stolen" from BEHIND the SO's back, they're unaware at all of the fact that their partner is off banging other lovers. So basically as a tl;dr, it's cheating without EVER being caught.
Anyways as far as I've seen I haven't spotted any of the above in this game so far (keyword "so far"), unless there's more and I'm just dumb because I don't know how far the game goes or if I can still advance the story farther, the only thing I've seen at all that covers the NTR tag as of this moment, has been involving between a side-character Oliver vs Fabe + Emma Love Triangle, which falls more closely under the category of "Netori" because Oliver is aware of what's going on between Fabe & Emma. It doesn't involve the MC yet at this point as his love interest is aimed more at Amelia, in which the love triangle here is between MC, Amelia, and Mia. In fact if anything at this point Cal has a grudge against the MC because Cal has a thing for Amelia, but Cals competition for Amelias affection is more competitive because of the introduction of Mr. Enyo's son, whom also happens to be competition to the MC because unlike Cal, Amelia actually seemingly gets along with him.