Romantic rivals. What can be said about them, other than they suck. You're friends with a completely amazing girl, ready for the right moment to turn the friendship into something more, and before you know it, out of nowhere some asshole steals your thunder. And it's always some jock/pretty boy/idiot/pothead/etc. who you know is undeserving of her. Or maybe their flaws just stand out to you more because you hate them. Romantic rivals. They can all go fuck themselves.