London, Feb 2: British singer-songwriter Lily Allen has once again topped the charts with her new single `The Fear', and she celebrated it by flashing her butt to her fans.

Allen, 23, was wearing an electric blue Little Bo Peep costume and stockings, a frilly top, lacy knickers and matching blue stockings with towering beige platform heels.

As she sang at London's G-A-Y club from her new album `It's Not Me, It's You', she cheekily bared her bottom to the audience.

"She's got a great figure with curves in all the right places. She looked absolutely fantastic," the Sun quoted Simon Roberts, 27, a fan of hers, as saying.

The `Smile' singer was later seen partying with her brother Alfie, 22, and his girlfriend Jaime Winstone, 23. (ANI)