YMMV / Gravity Falls S1 E11 "Little Dipper"

• Strawman Has a Point: The episode makes Dipper out to be the one who has to learn a lesson in not bragging over his constant wins over Mabel in various activities and games. While learning not to be obnoxious is a good lesson, Mabel is shown completely goofing off during their chess game which gives Dipper ample opportunity to win their match, which makes her come across as gaslighting Dipper because she's upset she's not winning games that she's not even trying that hard to win. Also Mabel had never actually acted like she was upset at Dipper's gloating before, making her revelation of the fact that it was actually bothering her come as a complete shock to Dipper, while Mabel's mockery of the notably insecure Dipper about his height was clearly upsetting him from the start.