Why would my dumper look at me while I’m walking down the hallway and then lock eyes with me?

We bumbed into each other recently after 8 months of no contact and not seeing each other.

I was walking past him ( he was sitting down with his friend). When I was walking towards him he looked at me. Then I wanted to steal quick glance and when I looked at him we locked eyes.

Why would my dumper look at me while I’m walking down the hallway and then lock eyes with me?
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