Mantua, I have wondered about you, and am sorry that this distressing situation has escalated.
Your H set up the boundaries that he promised to adhere to if you would agree to the new arrangement — no-strings sex in hotels, discretion, no dating, no overnights. He smashed those boundaries by developing emotional intimacy with OW, publicly dating/romancing her, and then moving to a physical relationship. They were holding hands in cafes, walking on the beach, shopping for her underwear, etc., for all the world to see.
At the time of your thread, H was bringing OW into your orbit. He was texting and smiling at her messages right in front of you. You were crushed that he took her to your family’s special restaurant the night before you, H and his siblings went there with your FIL. He also brought OW to his fix-up cottage open-house where she met his/your friends, even your best friend’s H. You felt confident that nobody caught on to their sneaky secret, but of course they would have been buzzing over their charade.
Now OW has met FIL. And although you previously stated that H would not bring OW to your house, it appears that they have indeed defiled your home. If so, she has played with your pets, sat on your sofa, slept in your bed or another, showered in your bathroom, used your towels and dishes, and looked at your family photos. I said before that OW was walking in your path, but this is beyond the pale. Where is your outrage?
Mantua, H told you that ‘nothing will change,’ but now everything has changed. They are a couple and soon everyone will know. You are being marginalized and your home debased. H’s lack of empathy and callous disregard of you is monumental. You say you work well as a unit, but that structure is crumbling as you contort and subjugate yourself. Do you really see value in living/traveling with a man who is happy to humiliate you with his adoration of another woman? 