Right there you stated to her what is acceptable and what is unacceptable.
but with no consequences or transparency it's useless.
It's called "cake-eating" here. She get's to be married, nice home, keeping up appearances, financial security and no obligations to her husband. Yet she has the thrill of a new, forbidden romance with no strings attached.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.