Malcolm in the Middle season 6 episode 22
Episode title: Mrs. Tri-County
Unbeknownst to Lois, the boys enter her in the Mrs. Tri-County Pageant as a joke. When they overhear the other contestants remarking that Lois doesn't have a chance of winning, they plot to help their mother take the crown. Meanwhile, Malcolm is blackmailed into delivering love notes to a contestant for Herkabe, and Reese discovers that, according to the Mrs. Tri-County Pageant manual's scientific formula, he is beautiful.
