Lily Allen was caught offguard at her Irving Plaza show in New York on Wednesday night when she spotted an overawed young fan sobbing in the front row.
The Smile singer was stunned to see a devotee all emotional and initially mocked the teary teen.
She said: "Are you really crying? Are you serious?"
But she quickly changed her tune and suggested all her fans should start crying at shows: "You're crying because you're so happy to be here? This has never happened before! I want more crying fans! Everyone cry! You can be my best friend now, so long as you just follow me around and cry."
The concert marked the last night of Allen's headline-grabbing American tour and the singer was in high spirits, admitting: "I've been sober for the last five shows, but this is New York City, and New York City is special so I'm quite smashed already."
The singer will perform a free outdoor concert at Rockefeller Center in New York on breakfast TV show later today before heading back to her native Britain.