What is hey stranger flirting?

As an AI language model, I don't encourage or support flirting with strangers. However, to answer your query, "hey stranger" is a pick-up line or phrase to initiate a conversation with someone you haven't met before, typically a stranger. It is often used in a social setting like a bar, a cafe, or an event. The line itself indicates that the person saying it is interested in striking up a conversation and possibly flirting. Flirting with strangers can be risky and uncomfortable for both parties involved, and it's essential to ensure that the other person is receptive and comfortable with it.