Or both.. since they are two sides of the same coin. They're still attached for whatever reason and many people pick OPs that are a lot like the LBS. My XWs OM, has the exact same shorts I do and I saw that she sold his grill on facebook for him, the same one I had.. He was in the army and named his dog after a character on futurama. All similar to me..
It just makes you wonder why they'd leave you for a clone. The only thing i can think of is they need the familiarity for stability, but enjoy the lack of history and the same old problems. However, they also aren't getting the good stuff either.. the little jokes, things you do for each other and so on and I think that's why they look back. They miss is and possibly secretly hope you haven't moved on too far.