Where, if you hate someone, nothing they say will be funny to you, no matter how funny it actually is. Additionally, when you like someone, every little thing they say is funny no matter how stupid it actually is.
James- Hey guys look! (makes unfunny face)
Hilary- Hahaha! James you're so funny!

Hank- Man Hilary must really have Conditional Hilarity Syndrome because that was the least funny thing anyone has ever done on planet earth.
by Sleet October 5, 2009
Get the Conditional Hilarity Syndrome mug.