Watch your ass

Posted by Joe May 16, 2009 at 20:09In reply to Watch your ass posted by Smokey Stover on May 16, 2009 at 16:22:

"watch your ass'"
"watch your tail"
"watch your six"

Dates from WWII, 1917, likely first British then universally from WWII aviators and military. The everyone picked it up.