The Simpsons season 23 episode 13
Episode title: The Daughter Also Rises
Marge and Lisa's mother-daughter Valentine's Day plans take a turn when Lisa meets Nick, an intellectual romantic who shares the same passion for culture, history and literature. Lisa and Nick fall head over heels for each other in a fairytale romance and make a secret getaway to Mulberry Island to profess their eternal love. Meanwhile, Bart and Milhouse are inspired by the hosts of "MythCrackers" to "crack" Springfield Elementary's own legends.