A agree that it is a tactic by H to legitimize his R with OW.
I know you don't want to influence your D in her R with Dad, but I still say, she is not an adult and therefore the decision to go away with two unmarried people, especially while still married to YOU, is not the example a good parent would want to set, and shouldn't be her decision in the first place.
As distastful as it may be, perhaps you should talk to H (calmly) about it, perhaps he can see reason. I'm dreaming, aren't I?
