COMMANDO WORLD OF JON HAMM

"KEEP your junk in your trunk and stop going commando!" That's what the cast and crew of the Emmy-winning series Mad Men are saying about star JON HAMM's bizarre "no underwear" rule!

Hamm, who's notorious for skipping skivvies, even has bloggers going nuts over
his not-suitable for- work attire, an insider told The ENQUIRER.

"Jon refuses to wear underwear and there have been so many close calls on the set that someone finally had
to tell him to secure his goods," a source confided.

"During filming, his character has had to wear some very short shorts, and that's when everyone's especially on edge. Some of the actresses and crew members wouldn't mind a sneak peek, but the majority of the cast and crew don't want Jon to accidentally expose himself."

Hamm - who plays brooding ad man Don Draper on the hit AMC series - is "getting a kick out
of all the fuss," says the source.

"Jon thinks it's hilarious."