Having earned rave reviews for her return to the stage, made the most of her tour success by partying with her 'West End gang' on Saturday.
The singer, 40, has been touring the country performing her comeback album West End Girl, with songs inspired by her turbulent split from husband David Harbour.
After taking to the stage for her second gig at the London Palladium, Lily enjoyed a night of partying with her friends including at the Broadwick Hotel.
The star danced the night away in a slinky white satin camisole as she enjoyed drinks with her pals, with both herself and Kelly documenting the night on Instagram.
Kelly, who was devastated by the death of her beloved father Ozzy in July, opted for a chic all-black look as she partied with her pals Genesis and KIINICKI.
While hundreds of fans have flocked to the capital to see Lily in concert, many were left disappointed when the star skipped the stage door so she could join her boyfriend Jonah Freud for dinner in Soho on Friday.
Having earned rave reviews for her return to the stage, Lily Allen made the most of her tour success by partying with her 'West End gang' on Saturday
The singer was supported by her pal Kelly Osbourne as she and her pals celebrated her tour at the Broadwick Hotel in London
Lily has been touring the country performing her comeback album West End Girl, with songs inspired by her turbulent split from husband David Harbour
Lily's romance with Jonah is her first serious relationship since the end of her four-year marriage to star .
The couple's explosive split and allegations that David was unfaithful led to her penning the breakup album, West End Girl.
West End Girl was critically acclaimed and reached #1 on the Official Album Downloads Chart, with the cover work going on display at the National Portrait Gallery.
The painting, which showed Lily in a blue padded jacket, a lace mini skirt and spotted boots, was created by Spanish artist Nieves Gonzalez.
Lily said: 'I'm so pleased to make this special painting available for everyone to see.
'Nieves captured the feel of the album so brilliantly and I knew immediately it would make a very strong album cover.'
'It seems to me the portrait reflects so many facets of the album – strength, power, vulnerability, determination and confusion, amongst many others – that it acts as a key to the whole listening experience. I love it.'
Nieves said she was 'overwhelmed' to have her artwork displayed in the National Portrait Gallery, and she felt 'enormously fortunate' to be part of the West End Girl 'journey'.
The star danced the night away in a slinky white satin camisole as she enjoyed drinks with her pals, with both herself and Kelly documenting the night on Instagram
While hundreds of fans have flocked to the capital to see Lily in concert, many were left disappointed when the star skipped the stage door on Friday
West End Girl was critically acclaimed and reached #1 on the Official Album Downloads Chart, with the cover work going on display at the National Portrait Gallery
Kelly, who was devastated by the death of her beloved father Ozzy in July, opted for a chic all-black look as she partied with her pals Genesis and KIINICKI
The star shared her own snaps from the evening on her Instagram Stories
She added: 'I wanted it to be an intimate and direct image, but also powerful. To show her strength, her wisdom, through the eyes of the contemporary women that we are.
'That balance between the classical and the contemporary was essential to me.
'This work reflects how art and music come together in the act of creation, with all its layers and facets.
'Using the language of the great historical portraits is not about looking back, it's about claiming that authority and putting it at the service of a new narrative.'
The West End Girl album is famously an ode to Lily's ex-husband David, 50, and their acrimonious breakup, and the star is currently touring the country following its release.
In her downtime, Lily has been enjoying a romance with Jonah - who is the son of entrepreneur Matthew Freud and ex-wife Caroline Hutton and the nephew of celebrated late artist Lucian Freud.
The pair have been spotted on multiple dates and seemed to take things to the next level by jetting to together - reportedly staying in a suite at the Hotel Locarno, thought to cost around £800 per night.
Lily and Jonah were also spotted kissing at her celeb-packed Christmas party at London's Stringfellow's in December.
The Smile hitmaker shared her relationship status in an interview with Grazia magazine, where she was asked who the last person was who has texted her.
Lily replied: 'My boyfriend.'
Last month Lily and Jonah were pictured enjoying a coffee break after travelling to Rome for a trip away together.
Spotting the pair in Rome, a source told The Sun: 'We walked past her and it was my daughter-in-law who recognised her and went, "Oh my God, it's Lily Allen."
'We did a double take, and it was definitely her, she was with Jonah Freud. They were just having a coffee and a cigarette together.'
Meanwhile the month before, Lily was spotted enjoying a cosy-looking dinner date with Jonah in a west London restaurant.
The outing marked the first date the singer has been seen on since her fling with actor James Norton earlier this year.
