Why did my crush fist bump me?

He would walk up to me as I ate my lunch during break, hold out his fist, not sideways but up and down, fist bump me, then he would turn and walk away. Him turning led him to still look at me and proudly point at me while still smiling. While he did this, he looks a few seconds longer. He wouldn't stop looking until he left the room. He did this like 5 times. I'm scared to lose him though bc of COVID closure like what if he doesn't feel the same he did.
Why did my crush fist bump me?
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