The Simpsons season 31 episode 21
Episode title: The Hateful Eight-Year-Olds
After severing her sibling ties with Bart, Lisa attends a sleepover at her new friend Addy's house, only to discover that Addy's clique are a group of cruel snobby rich girls that taunt her. Meanwhile, Homer takes Marge on a sunset cruise for the evening and finds himself at odds with the boat's cover band.