What does it mean if a guy initiates eye contact and continues to hold it after you break it and then look back?

For context: We know each other, but haven't seen each other in a couple of years. We both happened to be at a decently crowded event and I happened to glance over and find him looking at me from across the room. He didn't have much of an expression on his face, but seemed to be staring intently into my eyes, enough that I found it a bit intimidating. I broke eye contact for a second or two, then looked back and he was still looking directly at me. I broke eye contact again because someone started talking to me and am not sure if he still looked after that, and I didn't see him again that night (the event was ending).

Does this mean anything or just a coincidence?