NLT you have an unusual MLCer who values you (mine doesn't, and makes that very clear). Also you are handling it well. Which is what always causes me to make comparisons with Holly, who I got to know on and off the boards.
You cannot, as you know, regulate the behaviour of your husband with OW, but you can, if you wish, point out the consequences to him. That sooner or later your daughter will realise what is going on for example. If you could have a pleasant conversation just asking him if he has considered what will happen if your daughter puts two and two together, and how she will then feel?
Incidentally I do not think it is bad dbing to tell a MLCer that an affair will do damage to the marriage. It is a fact, it has damaged the marriage, and your husband doesn't care.
Right now if he had to choose between OW and you he would probably choose OW, that is true, and it isn't sensible to push that choice on them. Gradually he will come to see that he has problems, and maybe deal with them. SO I agree no ultimatums but that is not the same as boundaries.
My xh knew OW1 was trashy, and that was part of the allure. I think you are handling it so well - the iron fist in the velvet glove -
