Haha fuck no, dumbass. The only illegal thing is things that require consent. Flirting isn't one of them, it's not illegal, no matter the age. It is true that it might have been a bad thing to do, but if it's seemingly playful & doesn't hint at anything sexual or real-life activities, it's not illegal. So pipe down! Stop calling my girlfriend names, and argue somewhere else on the internet.

ChatGPT also verified this:
Laws regarding interactions between minors can be complex and vary depending on the jurisdiction. While flirting itself may not necessarily be illegal, it is crucial to consider the age difference and the potential for inappropriate behavior or harm. The primary concern is ensuring the well-being and safety of younger individuals and protecting them from any form of exploitation.