Why does a much older male coworker flirt?

He seems about 53-62 years old if I had to guess. He is becoming more and more flirty. At first I took it in stride like he was totally joking. I remember when he joked about being jealous of the thought of other guys texting me.
The weird part is this man doesn’t even know my name. But I know his. Yet he’s started touching me whenever he can. My arm. My shoulder. What is up with him?

Why does a much older male coworker flirt?
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