The other name for the FriendZone.
Awesome, Sweet guy: (To Girl) You know, we'd make a great couple... Will you go out with me?
Girl: No! You're like a Brother to me! My best friend! I don't wanna ruin our relationship!!
The Dude: ....
2nd dude: You've just been sent to the Ninth Circle Of Hell, man. I'm so sorry.