Why do women call their female friends "girlfriends"? For example: "I went out with my girlfriend 'Jane' last night." Women never say "I went out with my boyfriend 'John' last night" unless they're talking about their specific male significant other. Guys never say that they went out with their boyfriends unless they're gay, and we use the term "girlfriend" only when talking about our specific female attachments as well.
Why can't women just say "I went out with my friend [insert female name here] last night"? Is there some kind of intractable bond among women in which they are all girlfriends? Men never need to clarify these kinds of things, we're all just friends.
This... this is why "Seinfeld" went off the air.