Don't beat yourself up NLW, it's natural to feel a little vindication over something like that.
The WAS's new life with OP is rarely the nirvana they expected. In a lot of ways it's better if the affair never goes physical because the WAS can maintain the fantasy a lot easier. Once it goes physical there's no hiding from the fact that the new person has their flaws too, but worse, the WAS is still carrying all the baggage that they thought they were leaving behind when they ditched the LBS.
But the WAS is on their own journey, there is nothing we can do to speed them along other than to give them time and space while we work on ourselves.