It was a romantic comedy on the set of 'Prime Minister and I'! Behind-the-scenes photos captured the hilarious antics of lead actors Girls' Generation's YoonA and Lee Bum Soo. Lee Bum Soo helped out a drunk YoonA who looked clearly out of it with her various puppy dog expressions. YoonA also received acting tips from her veteran counterpart who made funny faces of his own while filming the scene at Namtaeryeong, Seoul last month. 'Prime Minister and I' will premiere on December 9 at 9:55PM KST on KBS2!