Season 22, Episode 12
Bart sees a dirt bike for sale and is intent on getting it, even to the point of getting a grade 'A' at school. But despite this, he feels angry with Homer for not buying him one, so he cuts a deal with some Chinese officials to get them some info on Homer's nuclear powerplant in exchange for the bike.... little knowing that one is already waiting for him back home.
After having a mummy-daddy moment, Marge comments to Homer "I just hope the kids didn't hear us" - camera pulls back to reveal Ned Flanders standing at his window with his boys all with shocked looks on their faces; "Well maybe your kids didn't!" That gag never fails to win laughs.
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