I don't know if a woman cares much about the feelings of her husband when she cheats.
It would be hypocrite if she continues to cheat and tells to herself that she cares about her husbands feelings, who looks like a picture of misery.
Vivian should have quit the affair on her own when Hutch made the proposal to open up the marriage. (this was the last exit before it gets really bad)
She must be naive if she thinks it does not have any consequences along the way.
It hurts the husband in the first place and later she gets hurt, because the marriage will be destroyed beyond repair.
It's like a boomerang, she has the fun now and later the pain.
She will get dumped by the husband and lover.
Vivian should not have cheated in the first place, but otherwise we would not have a game.