Well, technically Aura and George broke up, so anything from that point onwards no longer qualifies as NTR.It's getting there. Last I checked they were working on some stuff with George and him finding out a bit of what is happening. But it certainly is a game about her cheating and justifying it as being "not real" so I feel NTR is a perfectly accurate tag. it isn't specifically a shame kink, right? Isn't it just cheating? I don't have interest in it, so I admit to being fairly unknowledgeable.
You could split hairs on what is NTR or not, but for me like I said, it's just that this game doesn't scratch that itch.