Lily Allen attempted to punch a woman outside a London nightspot in the early hours of Tuesday.
The incident took place after the unnamed passer-by allegedly hurled abuse at the "Smile" singer outside Ronnie Scott's Jazz Club. Lily then retaliated by trying to hit the woman three times.
The woman is said to have laughed off the incident as Lily was taken to a waiting car by her friend, TV presenter Miquita Oliver. In the process, Lily exposed her breasts.
A source said: "A woman outside started shouting to Lily and she just lashed out at her - though she missed with her punch. "Not surprisingly, the woman didn't seem that scared by Lily. In fact, she seemed more bemused by it all."
The 23-year-old singer was reportedly in a friendlier mood earlier in the evening, laughing with photographers waiting outside Soho's Groucho Club as she playfully punched the air as she left the nightspot.
This is not the first time Lily's temper has got her into trouble. Last year, she was arrested and cautioned for kicking a photographer after a night out in London.