The Fairly OddParents - Season 8 Episode 10 -

Doug Dimmadome selects the Turners to go on a space mission, but it turns out he was really Dark Laser in disguise, with an elaborate plan to take revenge on Timmy and trap the Turners in a space zoo on his Death Ball. In this episode, Timmy's parents are revealed to be more intelligent than before, because they (smartly) say the opposite of what they want so Dark Laser will do "terrible things" (opposite of what they want) to them.