Puppy, you seemed very opposed to the idea that an LBS can know about an affair and NOT have that affect their self-esteem. I am fairly sure my H has an OW and my self-esteem is just fine. Because I know that any R he is having is NOT healthy.
Just posting what my experience and observation has been, Albuquerque. It is a rare bird, indeed, who can stand for more than 6 months or so without it affecting them in some profoundly negative ways.
That being said, you here on this MLC forum are not a representative sample. You are, by definition, some of the most steadfast, patient people I've encountered, and your wonderful support system for each other allows you, I think, stand for much longer periods of time.
I'm not saying it can't be done. I'm saying that average person can't do it for very long. Again, that's been my experience.