Last, flirting with co-workers is another touchy subject, and is bound to happen, especially if you work or go to school in a very co-ed environment. We all need a "cheat day" sometimes. If you take a girl for granted your basically putting the nail in the coffin of your own relationship. Something to keep in mind, wether you're a guy or a girl: we often contribute to our partners shady behaviour more than we would assume. Sometime we contribute to peoples shady behaviour more than we think. Girls take their family and friends opinion very seriously, especially when it comes to romance.