Codename: Kids Next Door (2002)

Season 3: Episode 7

Feeling that Numbuh 1 must take a day off, the team force him to go to the beach, telling him to have fun or else. Nigel makes an honest attempt - until a crab swipes his swim trunks! After suffering a great amount of public embarrassment, 1 makes his way back to the Treehouse... and minutes later, walks out of his room to tell his terrified team that he's resigning from the Kids Next Door! After he leaves, the purpose becomes quite clear... an envelope is found in his room from the Delightful Children, with a picture of his tush and a note saying ""Leave your team behind or we'll put your behind in the school yearbook."" Now Numbuh 1 is heading for Delightful Manor, where the evil peeping toms desire to make him one of them! Can the team save their leader from the sadistic shutterbugs?!