guess i always thought about swinging as in couples not one of them..
and thats not actually quite true i would say as in she's roleplaying ...that's how i would look at it.
as mentioned in game at one point Karen DOES TRY to dominate her to more than 1 mean and when she is not feeling it (Molly i mean) they get shut down fast and hard as mentioned again by Karen when she try to do things Molly was not into it and was not willing to roleplay...so thats why again i say this is not really NTR its a acted fantasy with constenting adults ...
I don't recall that exact segment, can you tell me where she goes too far and gets shut down? I recall her saying "I'm not a lesbian," almost rejecting a girl, but even then immediately after "mistress I'd love to tongue you anywhere anytime." The only reason she rejects one girl is to get her dom feelings out and get dominated by her. So with Karen she quickly submits to her, even walking around naked for her.
Role playing is part of sex. I'm not saying she literally became a sex slave, but definitely enjoys the role of being another girls sex slave.
Also, I do wanna mention, she does do this behind the mc's back. Where the mc gets exclusive permission even getting permission (insistence actually) to not need permission, the wife does this intimate play with someone without even discussing with her husband ahead of time. Actually she does this quite literally after a talk about how she wants to remain faithful to the mc for life. This game assumes guys aren't possessive of women when it comes to other women which is why the mc doesn't seem to make a big deal of the wife in bondages licking another girls asshole without his foreknowledge.
But if you're not the type to enjoy the content, don't go for the content. I think the wife really was out of line on this one as all fetishes and partners should be discussed ahead of time... if you were worried about lesbian ntr you probably wouldn't like this scene.
As an edit, another point I wanna make is if the wife willingly did the exact same with a *guy* (giving him head, calling him master, licking his asshole without the husbands knowledge) there'd be no question an ntr war would begin on these forums. If someone asks about lesbian ntr just assume the dominant character is a male and the jelousy that they might experience in a self-insert of the mc (not strictly the mc) and you'll have your answer of what they wanna know.