Not at all surprised by this development. I had many similar ones in my M where he was going to stop seeing OW1 and recommit. Never lasted more than about 3 months.
I don’t see that this changes anything except your resolve needs to be stronger. All she learned is that the divorce bluff didn’t work. She’ll try another. With this attitude there will very likely be another/or the same OM, just hidden better.
I personally think you should still move out. How else do you change the dynamic? Showing her your strength now will yield more dividends.
