What was he up to/thinking?

If a guy goes out of his way to talk to someone from his past, while she's working and he's a customer, obviously he is either trying to get her attention or talk to her. If he is trying to "talk" to me, what would be his purpose?
We had dated a few years before, things ended with no hard feelings, just lost contact. This was the first contact we had since we lost contact. The contact happened at my job, half a dozen or so times.
I didn't really react to him because I wasn't sure how to.

What was he up to/thinking?
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