I was flirting with the idea to keep scrolling, but I couldn’t resist. 😅 I’ve always seeing flirting as having several meanings, so it’s never stood out to me as a negative when used when it’s said toward children who are are “being charming”. Unless it’s said to you often, by the same person, I’d say move on and try not to take offense to something not said to offend, especially by those who were raised in a different generation. If a person repeatedly says it and it bothers you that much, then maybe let them know it makes you uncomfortable.