An Uncle Bailey 

A sick perverted comments made, an action that crossed every line your mother ever taught you, an act so gross that all you could do was shrug your shoulders and say, "Oh, he/she pulled an Uncle Bailey" and shudder.
The initials "UB" also count.

After seeing a friend knowingly drink a spit-filled beverage..
Having a friend climb in bed with you..
Someone making a crude referance to something sacred or loved..
At seeing a flasher or someone wearing clothing they shouldn't..
"Oh, he/she pulled an Uncle Bailey/UB"

An Uncle Bailey by Matt Windt November 6, 2008