Colbie Caillat surprised a group of fans on Saturday when she showed up at the Central Perk pop-up shop in New York City and sang "Smelly Cat," a song made famous by one of the show's character, Phoebe Buffay (played by Lisa Kudrow).
"Smelly cat, smelly cat what are they feeding you?" she sang with the crowd. "Smelly cat, smelly cat it's not your fault."
"That was COOL! Singin @ #CentralPerk," the singer tweeted after her impromptu performance. "My favorite show ever #Friends20."
Last month, the entire cast of "Friends" celebrated the show's 20th anniversary.
Courteney Cox recently talked about how the group used to celebrate every new episode by watching the show together.
"We did. The whole cast," the actress told Jimmy Kimmel. "Maybe even [director] Jimmy Burrows and maybe the creators. We did it every single Thursday for like the first year."
Cox also joined Kudrow and Jennifer Aniston for a mini "Friends" reunion on "Jimmy Kimmel Live!," agreeing to act out some fan fiction supposedly written by the late night host.
Things took a turn for the surreal when Kimmel unveiled an exact replica of the sitcom's famous kitchen for the scene! Check out the hilarious clip below.
Do you miss "Friends" as much as we do? Sound off below!