The 'Wings' singer shook off any jet lag she might have been feeling from Little Mix's recent trip to America to party hard at Libertine night club in London on Wednesday (12 June).
She later tweeted: "Actually had the most amazing night was sooo funny love all my friends and family so much."
Dressed in a black pencil skirt and striped crop top, Jesy was joined by band mates Jade Thirlwall, Perrie Edwards and Leigh-Anne Pinnock, as well as showbiz pal George Shelley from Union J.
George was seen carrying the remnants of Jesy's birthday cake out of the club but, contrary to reports, did not drop it on the ground outside her house.
Jesy set rumours straight via Twitter this morning, saying: "P.s George Shelley did not dump or ruin my cake it was the leftovers from what had been eaten. The cake had a great night."
Well, thank goodness the cake had a good night!
Little Mix have just returned to the UK from a hugely successful visit to America, where they've been promoting their debut album DNA with meet and greets and appearances on shows including the widely-watched breakfast programme Good Morning America.
They even made chart history over there by beating a record previously set by the Spice Girls, zooming into the chart at number four with DNA. Spice Girls' debut album Spice entered the chart at number six.
There will be not time to rest, however, as this weekend they're off to the Isle of Wight for their first ever festival performance.