I dont care about general semantics or definitions, the only one that matters here is the one used for the site. And the ntr tag here is only used if it is the mc the one getting cheated on. Otherwise it is just cheating.NTR basically is one in a relationship KNOWS the other is cheating and is active witness to that.
That usually happens via active watching and usually by "allowing" the other to cheat or even initiate that him/herself.
For that reason Rachels father and mother come awfully close to NTR already, because the father watched/listened transformed as a bat.
Since Rachel is a vampire it can't be ruled out she followed MC in hunt mode/bat form and saw MC "helping" Sophia.
In very simple terms the main difference is knowledge.
If the partner has no clue about the cheating it is ... well cheating.
If the partner is aware of the cheating, watches or initiated it it basically is NTR.
Nopls just stop, discuss ntr im ever fucking thread. pls. stop it