Foster's Home for Imaginary Friends - Season 0 Episode 7

Mr. Herriman tells Bloo to sort the trash for punishment because Bloo hosted a mud-wrestling tournament in the living room. Mac comes along and talks Bloo into pretending it is fun so that other people will want to do it. Soon, he has everybody doing it. Mac tries to tell him that it isn't fun after Bloo refuses to go do something else. He thinks everybody is gonna take the trash for themselves and tells them to get out. Then he realizes it isn't fun without the guys and walks away, until Mr. Herriman comes in and tells him to finish sorting the trash.