Welcome to the slippery slope.
“you don’t want to cut ties with him”
“You don’t want to be out of his life!”
“What about when grandchildren come?”
So, you sign on to be a passive witness to every depravity.
Now, they want to come visit and all share a bedroom. What do you do? You don’t want to be “out of his life”, do you? So you let them do whatever they do in your house.
Now, they need some money, they ask you for a loan. You don’t want to be “out of his life” so now you’re paying for them to live like this.
Now they join a new-age spiritualist group. They want you to come to a baby-dedication-ceremony, where they ask Gaia to bless their child. Well, you don’t want be “out of his life”…
Instead, consider that you’re not doing his soul any good by being a mute witness to his sins. You may be actually doing good by standing up to it, clearly articulating your objection, and then praying mightily for him.