Sorry, I do feel badly that you are in this situation but right now I feel the worst for K. No one knows what he's going through or what he's really like. All you have is the word of a woman who lied, cheated, and manipulated the situation to get what she wanted and get you to like her BEFORE finding out that she was cheating and lying to you as well. For what? In hopes that now that you like her you'll forgive the fact that she's been lying this whole time?
IF! Big If there, K is as bad as she makes it out to be, yep, he's got his own issues that all this lying and manipulating is making worse. My thing is, unless you have met K and gotten to know him, I take what she says with a grain of salt. I'm sure he might have said or done some things lately that might seem controlling or harsh, but you don't know if that's who he is or how he's reacting to a wife who is lying and manipulating and now making friends with a couple that are helping her lie and cheat on him. From his POV, suddenly there's two people who are sleeping with his wife, lying about it to him, and now making him the bad guy.
Me: Late 30s pansexual poly.
DH: My husband of 19 yrs and father of 3 teen girls.
DC: LDR of +4 year