Codename: Kids Next Door Season 2 Episode 3

In "Operation: S.U.P.P.O.R.T. (Special Underwire Protection Proportedly Outfits Rotten Teenagers)", Numbuhs 1 and 2 go to Numbuh 5's house to protect Numbuh 5 from enemy attacks when she falls sick. But her teenage sister Cree arouses Numbuh 1's suspicions of her being an enemy of the KND, particularly when he suspects that her bra may be used as a weapon against them.