This coworker asked me how old I was then got weird when I asked them why they asked.

He's a young man I'd say 30s and he out of the blue asked me how old I was. I said 50 turning 51 why you ask? He got all cagey and said oh no reason and has been avoiding me ever since. Sorry but if youre going to ask me random questions about myself i have the right to ask why.