John Slattery Drinks Fake Gibsons on Set of 'Mad Men'
By: Rosemina Nazarali
Published: June 21, 2012

John Slattery's Mad Men character, Roger Sterling, always seems to have a Gibson in his hand. However, Slattery doesn't quite share the same tastes as his character, especially since the Gibsons he drinks on set are filled with water. 
"Isn't that just a martini with onions in it?" Slattery said. "The 'Gibsons' I usually get are actually water and onions. It's five or six in the morning -- they're not giving us real booze."