Can tell you about my experience...suspected something was up at the end of last year/beginning of this one, and after hearing her side of a phone call that was very reminiscent of the ones we had at early stages of relationship I asked her outright if there was anything she needed to tell me. Of course it was lots of 'I don't feel the same any more' but no mention of anyone else, and my suspicions were only confirmed when she accidentally put something through our joint amazon account, revealing her new address (OW's) a few short weeks later.
Prior to this she tried to force through a house sale quickly (me buying her out), days within breaking up, hoping for goodwill in the process before it became apparent what was actually going on....I held out as I wasn't financially able to anyway and was especially glad that I did when I realised she was trying to take advantage of the situation. She has not got as good a deal as she had hoped, although in current market values it is more than fair, and I paid all costs of transfer. So, anyway, I am glad I did that on my terms and she didn't successfully manipulate me when I was unaware of the full situation.
Cut to now her and the OW are trying to sell the place they are living in, and it is likely to go for many thousands less than what the OW paid for it 2 years ago. They are in a very tricky situation. So financially, at least, things are really not going very well for them.
I don't really care to know anything about their relationship, I have come off facebook so I don't see anything and remind my mutual friends if they begin mentioning her that I really don't need to know.
I actually spotted them in the park on Sunday, ex and I made eye contact at the same time and I suspect OW had spotted me first as she had turned her back to me and I suspect had just said to ex 'Don't be too obvious but that's Suggestions over there, isn't it?' I was walking in their direction and kept striding along to them. They turned at an odd angle and went down a different path to avoid me.
For me, honestly, I still feel differently at different times. Sometimes I think, yes, their financial situation serves them right, the way I was deceived and manipulated - karma has come back to bite. Other times I just wish her well and that she doesn't have too hard a life - that we are all just vulnerable, fragile, stupid people bumbling through life trying to do whats in our best interests whilst minimising the fall out.