7x15 "The One with Joey's New Brain"

Joey's Days of our Lives character has another famous one's brain transplanted into his body, and tells the actress by accident. Using his charm, Joey and the actress work to maintain the character's legacy, and they sleep together. Ross cooks up a special surprise for the wedding: dreadful bagpipe playing. Meanwhile, after finding a cute guy's phone, Phoebe and Rachel compete over who gets to keep the phone to start 'a fairytale for the digital age'. Later, an elderly gentleman claims the phone, and Phoebe happily goes to dinner with him, finding him more attractive than the young man whose phone they thought it was.