Who do I expose to?

I talked to the father of my WW and he said he'd stay out of it.

Is it simply that they all know?

Do they need to even exert anything against it?

I did it on face book. She deleted my as a friend this morning! and the post as well.

I think the idea of exposure is to get everything out into the open. To anyone and everyone it might make a difference to. Friends, relatives, coworkers, bosses, anyone who may have respect for WS or OP. It's to bring the A out of the darkness, where it grows like mold, into the light of day, where it will wither and die. It needs a dark quiet place to thrive. Bringing it out into daylight, where people talk and accusing eyes probe is what is needed to kill the infidelity. Maybe even one or two bold individuals will confront them, altho that isn't a guarantee. Embarrassment, loss of respect, spiteful eyes all take their toll. And, while it may take a little while, it will most likely be the end to the A. Even if someone refuses to hold WS or OP accountable, they at least know what's going on. Most likely, if they are a normal person, they will not approve. It's hard to look at a parent and know they are disappointed in you. It's hard for any relationship, even a normal healthy one, to exist under those conditions.