While enjoying some mother-daughter time at a Valentine's day dinner, Lisa meets a Hemingway-esque boy named Nick who quickly sweeps her off her feet with his roguish charm and adventurous attitude. Marge is unhappy with losing the attention of her daughter and strives to keep the two kids apart. Lisa, with Grampa's help, tries to run away with Nick and share a kiss under a Mulberry tree; however, she is disappointed to find out that Nick isn't as adventurous as he seemed. Meanwhile, Milhouse and Bart, inspired by the television show "Mythcrackers," spend their time "cracking" school myths.