Guy's Behavior

Guys, What does it mean if a guy gives you a double take like he looked and looked again without me looking?

Backstory I live upstairs above a pub and the landlord works in the pub and has a son that works there on some shifts but also comes in when the bar gets busy. And it was busy that night but i came down later as things were quieting down, the guy I’m talking about basically was finishing his shift and just collecting glasses left on the bar. As he was about to put them in the kitchen he looked at me while “I wasn’t looking” i could see him in my peripheral but he looked again 2 seconds after, he looked at me again in the kitchen as he was signing out and looked again while leaving the kitchen to go. My friend who was stood next to me said she saw him from the first time he looked at me when I asked if she saw what I think I was seeing which bare in mind I never made eye contact with him any of the times he was literally turning his head to look at me. She said he looked nervous every time he looked as in if i were to look back at him he would look away but also like he couldn’t stop looking like he just had to. Also sorry for the literal paragraph I just wanted you all to know how it went like how I remember it I’m just intrigued to know if any of you have a clue as to why he would look at me like he did.

Guys, What does it mean if a guy gives you a double take like he looked and looked again without me looking?
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