Well, almost.

There are times when you are better off not flirting and there are places where you’re better off not flirting too, if for no other reason than the odds are stacked against you at those times or in those places.
Flirt with honor
Clearly, you don’t want to be flirting with a girl who is out on a date with her boyfriend!  Even if you do and think of yourself as someone who isn’t afraid to get into an altercation with another guy, you should always be conscious of the fact that the girl you are flirting with is already with someone else and as such there is a greater likelihood that she won’t welcome your advances.  Further, if it does turn into an altercation, she certainly won’t appreciate you for causing it.  Generally, women like men with honor and they also like men they can trust.  Do you think she’ll see you as honorable if you make your move when she’s with someone else? Do you think she’ll see you as trustworthy if right from the outset you demonstrate your willingness to try to get her to cheat?  Obviously not.

The basic rule of thumb is to not waste your time flirting with girls who are obviously already taken!

So, what happens if you flirt with a girl who isn’t with her boyfriend, only to find out that she has one?  Simple.  Once again, even if she’s being nice, the polite way to approach the situation is to apologize.  Simply tell her that you find her very interesting, but that you won’t bother her now that you know.  You can always ask her to remember you if ever her circumstances change.
The best places to flirt
Some people will tell you the best place to try to flirt with women is at a nightclub or a bar, after all, those are the best places to pick up girls, right? Not necessarily and, in fact, there are also a few good reasons why those aren’t the best places to meet girls.
You see, it is true that some girls go to bars and nightclubs to meet men, but others go simply to have a good time with their friends and to dance. Also, because it is common amongst guys to think of bars and nightclubs as the place to “pick up a chick”, girls who aren’t going there for the same reason will be in a defensive mode.  As a result, the odds of picking up at a bar and nightclub are higher if you’re lucky enough to approach a girl who is there for the same reason, but if not, the odds are also higher that you will be rejected outright before you even have a chance to strike up a conversation – assuming you can over the noise.  Further, nightclubs and bars are filled with other men competing with you for those women who aren’t on the defense, so in the end it all balances out to the point where the odds of rejection are just as high as anywhere else.

Rather than allow this knowledge to lower your spirits about approaching girls at bars, let it raise your confidence about flirting with girls outside of those bars.  The beautiful truth is that often your chances of success will be much higher when you successfully ‘connect’ with a girl in a place where she is less likely to feel defensive.

To avoid flirting at a time when she’s not going to be so defensive, don’t make your move when you’re both mostly alone in a private place, as she may feel concerned about your true intentions.  Don’t make your move on a girl who is clearly in a hurry, or who is preoccupied with something else that will suck her attention away (such as if she’s trying to talk to someone else).  The kinds of places where your flirting efforts will work best are those that are highly public, such as libraries, supermarkets, shops, restaurants and even in the street.