that's pretty much a classic, the good old 'he's just a friend excuse'. bet she banged him regularly while with you, one has to always have a look at cell phones, emails, and fb messages with cracking softwares.
I actually checked her phone.
This was after we broke up though. I had to move back home, which was 400 miles away, but couldn't leave for 3 days.
So 3 days post breakup still living together and sleeping in the same bed. Weird.
Anyway, I checked her phone out of curiousity (I would never have done it when we were together
) and she had lots of texts from this guy. Nothing indicating they were fucking but still, she said she hadn't spoken to him regarding the breakup yet there were 40 messages or something sent in the last 2 days...