overall though this standard stuff in any social drinking environment.
girl wants to watch her bf "in action" so she start flirting with guys in the bar. . just so her bf will step up and "defend her honour"... crap like that happens all the time. the gf/bf team do it for fun.
when i'm in a "club scene" or social drinking establishment and a really hot girl i've never met before starts making up bullshit reasons to talk to me the first thing i do is look for the bf.
its a lesson most guys i know learn by the time they are 20 at the latest.
(drinking age in Canada is 19).
i have a good friend who is approximately the size of brock lesnar. this stuff never happens to him though.

it does not happen too often to me.. i'm 6'1".
what i find is... the smaller the guy is the more this crap happens.