A “Girl Thing”

This is something I call that thing where a woman does not believe that women and men can be just "friends." A woman who does the * "girl thing" will become increasingly unhappy if her boyfriend, husband or significant other has friends who are women. A woman who does the "girl thing" will also display varying degrees of hostility toward other women to the point where she is not actually able to form a lasting friendship with members of her own gender due to being in a state of perceived competition with every other woman out there. (Paradoxically, or perhaps hypocritically, the woman who does the girl thing will often declare that she prefers having male friends. Logically, you would think that the woman who does this would avoid having male friendships to avoid "poaching," someone else's boyfriend, but no.)
When I was much younger, I very much assumed that this was the default setting!