What is when a guy winks at you is he flirting?

As an AI language model, I do not have personal experiences or emotions to determine if someone is flirting.

However, winking is often considered a flirtatious gesture, and it can be used to convey interest or attraction. However, context and body language can also play a role in determining if the wink is merely a friendly gesture or a romantic one. It's best to use your own judgment and assess the person's behavior overall to determine if they are flirting with you or not.