How could someone else be reading my messages?

[AC Question]

Someone else reading my messages ...

This will probably sound impossible, but, it is happening ...

There are three other people involved, I'll call them Bob, Joe and Kelly. They don't know each other, they all live in different counties and have never met. I know all 3, but have never met or been in the same town as Kelly. I have conversations via SMS and Whatsapp with all 3 individually.

Now, Bob is contacted by Kelly and reveals information about my conversations with both Bob and Joe !!!

Not just general information, but specific phrases like "condom catheter" (Joe cares for the elderly) and an odd Welsh village.

How has Kelly got this information?

I have an HTC One M2 which had a factory reset before the specific phrases were used and Kelly has never sent an MMS and we don't use Whatsapp.

I also use complex passwords ... 10 chars, mixed alpha numeric, upper and lowercase and symbols.

I'm not sure whether the phrases were in SMS or Whatsapp.

My guess is that Kelly has compromised a backup location, or something.

Anyone any clues as to how she is doing this?

What is the most likely weak link?

Thanks,

Abi

ps names have been changed to protect the guilty

 

[B. Diddy]

Re: Someone else reading my messages ...

Welcome to Android Central! Is it possible that any of the messages you sent to Joe also included Kelly inadvertently as a recipient?

I don't use WhatsApp, so I don't know if this is possible--but could Kelly have seen your WhatsApp contacts (just like you can on other social networks like Facebook and Google+) and "friended" Bob and Joe, and then carried on some separate conversations with them?