It isn't the act of sex that is the problem for me. It's the humiliation that seems off to me. I'm fine with the girls being intimate with the others, that's not a problem. The act of being taunted with the video is the aspect that bothers me most. Even if the mc gave zoe permission to act on abby...the video being waved in front of his face feels like a betrayel of trust to me.
And my definition is actually pretty narrow. As far as I understand, cuckoldry isn't about the cheating so much as it is about the sense of inferiority and humiliation. The cuck can still get off if his or her partner is masturbating them while degrading and humiliating them. A game that shows this aspect best is "what's mine is yours". A game that explores various kinks/fetishes. So for my point, I don't think the act of recording is necessary, even if they are lying about having recorded it, it would (albeit arguably) sort of be cucking him by humiliating him. Maybe he gets to see it...but I'm afraid of going further and being disappointed...because I do enjoy the game...
As for the sharing part, that was more a vent then being serious. The game has me a little too wrapped up in it...and I needed a dumb joke to relieve a bit of the pressure...