Tulisa was invited to celebrate Vanessa White's 24th birthday on Saturday (9 November) and tackled some disco hits with Vanessa's bandmates Rochelle Humes, Mollie King and Una Healy.
The only person missing from the celebrations was new mum Frankie Sandford, who gave birth to baby son Parker on 18 October, but Tulisa had no problem temporarily filling her place!
Tulisa, who was sporting new blonde hair extensions, appeared to be in her element as she grabbed the mic alongside the girls.
Posting a photo to Instagram, she said: "I was the 5th member of The Sats last night, karaoke time."
The N-Dubz star wore a black and white checkered top teamed with black leggings, and shared plenty of snaps from the night.
Posing alongside Rochelle and her husband Marvin, Tulisa said: "Me and the dream couple. Love these 2 so much @rochellethesats @marvinhumes xxx."
In another photo, Tulisa cuddled up to birthday girl Vanessa. Captioning the photo, she said: "Look which sexy bday girl I'm with @vanessathesaturdays.
Vanessa was also joined by her boyfriend Gary Salter, while Una came with husband Ben Foden.
It was a long day of partying for former X Factor judge Tulisa, as she also popped over to G-A-Y, where she reunited with Little Mix.
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Watch Tulisa's music video for 'Young' below: