George Clooney I'm Horny and It's Hilarious

2/10/2012 12:10 PM PST


George Clooney ... plus Stacy Keibler ... plus an air horn ... equals practical joke caught on tape ... and it's hilarious.

Clooney was leaving his favorite L.A. Italian spot Dan Tana's last night ... when he totally set up our photog ... and then blasted the guy.