Along with above, I would say that any sharing/swinging coming under the NTS label, that involves a separation of characters, or non-involvement of one or other partner consent-wise, isn't actual sharing/swinging.....just cheating or at the very least betrayal.
That's when it becomes NTR to me.
Just like TACOS...sure it has consensual swinging and sharing, but there is a crapload of NTR too (she only tells him what she wants him to know mostly). Which is ok, because MC just wants her to be a slut, everything else in incidental.
Not saying I wouldn't play the game, but I would wanna know that it's gunna happen going in. Which is stated up front in TACOS, but so many devs just chuck it in, halfway through, even against player choices sometimes.
Hence why I always check dev notes, reviews and tags before downloading anything.