I'm tempted to focus on the part where Holly's husband has control issues. Or something. Honestly, he's okay with having a girlfriend, but he's not okay with his wife having a girlfriend. Talk about having your cake and eating it.
That really doesn't sound like a poly ideal.
I hope Holly isn't trapped in some sort of an emotionally abusive relationship. It sounds like you have your head on your shoulders, but I would worry about you a little bit, that you would internalize some of this as saying something negative about you.
Thanks for writing about this, and I hope it helps you process and come to terms.