A clothes shop was running a promotion giving away free jeans. In order to get the free jeans you had to try a pair on, then, while still wearing the jeans you had to put your right hand in the left pocket and your left hand in the right pocket and reach right to the bottom of the pockets at the same time. Many people tried but were unable to achieve the feat until one chap walked in and walked out a few minutes later with his free jeans.
How did he do it?