Ugh, portia, sorry it is rough for you. I cringed when I read your H said he was "interested" in dating someone. My H told me when I found out about his then EA, "we have a mutual interest". That hurt, when I found out he had been lying and thought AW was an answer to his issues.
I agree with job. It's sad they look to external sources to solve their happiness and who knows if they ever will grow up? and who wants to be a backup plan after YEARS of knowing someone?
Sending hugs your way.
Me:49 H:47 S: 16 T:27 M:25 My EA: 2001 His PA: 10/2007, 6/2013 Separated, but H still in house
Find your Shambala: a place of peace and happiness.