CHICAGO, Sept. 11 (UPI) -- A Playboy magazine stolen last week from a Chicago bar's bathroom has been returned, the bar's co-owner said.

A framed copy of the May 1970 issue of the magazine was taken while others were simply left behind, the Chicago Tribune reported .

The bar's owners, Scott Weiner and Greg Mohr, offered a $100 gift certificate to The Fifty/50 (their bar) and a copy of Playboy from May 2009, signed by model Crystal McCahill for the safe return of the stolen Playboy.

An anonymous man came to Weiner Thursday and handed him a bag containing the missing Playboy.

"(The man) looked nervous. There was a sense of embarrassment on his face," the bar owner said.

The man told Weiner a drunk "friend" stole the magazine, Weiner said.