guy won't tell me his age. is this a red flag?

this guy that has been helping me as a service advisor has been flirting with me via text and won't tell me his age. he asked for my instagram account. I am 29 and he says he is a lot older than me that he is ashamed to even tell me. I got the wrong impression that he was younger because he said he is learning english and is in school for his bachelors. is that a red flag?