The Simpsons Season 13 Episode 20: Little Girl in the Big Ten

Lisa tries to fit in with two college students by lying about her age. She finds that the college atmosphere is perfect for her, but her lie is soon discovered and she is shunned by her fellow elementary school students. Meanwhile, Bart is diagnosed with a weakened immune system after getting bitten by a Chinese mosquito and must live in a plastic, germ-free bubble.