Just inform S and that's it. Then go read about Triangulation in relationships.

As for W living the consequences, people tend to justify their own actions. I'm sure she is not happy and I agree that when ideals and actions misalign, that it is often projected in physical health and appearance. But most W tend to rationalize by external locus. Meaning they tell themselves that "This" is happening to them, instead of they are doing it.

I know, heady stuff.

Do you plan to be there as she cleans? It might be an opportunity to mix things up.

M 53 W 54, M since 98
D15, D19
8/2013 discovered EA, W maintained contact with OM
until 10/14
7/2/17 W said she wanted S, 7/25/17 moved out of MBR
12/17 W says moving out 5/18, W still in home.