I think it's fairly likely that he's now meeting most of her ENs.

Hey Gurka - Hopefully she's not starting up a new relationship, but if she is, then it's probably good that you're seeing this now rather than later.

For now I would continue with your long distance Plan-A. Your latest e-mail is great! Let's her know that you're still concerned about her father, and a little bit about what you've been up to... and most importantly, no relationship talk!

she seemed be calling her ex-boyfriend a lot (they've remained friends) after I exposed the affair.

So were you able to verify that she was calling this former BF by the phone records before she switched phones?

If your gut instincts are telling you something else, then by all means start snooping and see what you can uncover! Like I mentioned at the start, it's much better to find this out now, than later on down the line after you've invested several hard weeks/months of Plan-A.

If she's already involved in another A, (perhaps only an Emotional Affair), then I'd seriously consider another COA...

Semper Fi,