Analysis of information sources in references of the Wikipedia article "Flirting" in English language version.
The first known use of flirt was in 1580
Q: I'm a guy who loves to flirt but it can get me into trouble. How do you judge the line between harmless flirting, seduction, sexual harassment, leading someone on, being inappropriate, and so on? It feels like a social minefield. A: It seems that some form of flirting is universal in social intercourse.
HE SAYS: ... German women, though, have become conditioned to a much more subtle style of coquetry. Interest is indicated by way of a studied, concentrated look on the part of the man -- a gaze which may, but often doesn't, include a smile. Rather than a stare, though, the look should be brief and fleeting -- and the man's job is done. In a German-on-German flirt, the power rests solidly with the Fräulein. [....] SHE SAYS: ... The bottom line, though, is that it is often up to the foreign woman to break the ice in a way the German man understands: heavy on the warm-yet-serious discussion and lighter on the flippant-friendly-sexy thing. Flirting in Germany is not nearly as fun, meaningless or flattering as it is elsewhere. But the sometimes awkward but also deliciously subtle dance between the genders here might just grow on you.