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On the October 3 broadcast, the cast sat in a pizza parlor to plan their day when a man in a helmet, seemingly the delivery boy of the pizza parlor, barged in and walked in front of all the cameras, interrupting filming. The cast members were fooled at first and wondered what the delivery boy's intentions were, but when he emerged a second time, they became more and more suspicious. But what ultimately gave Heechul away? The staff's poor acting! Noticing the PD's awkward acting while pointing to the delivery man, MC Yang Se Hyung immediately accused the PD of ruining the hidden camera prank.

Once the cast began singing "Sorry, Sorry" to get Heechul to reveal his face, Heechul finally stepped out and took off his helmet, then began yelling at the staff! He shouted, "I told you it wouldn't work! Why do you guys have to embarrass me like this!"

Meanwhile, 'Street King' consists of a format where the cast members go back to memorable neighborhoods from their childhood or past to play games and become the 'Street King' of the day. Check out Heechul's failed hidden camera prank above!