A jubilant looking Simon was seen leaving the fancy Arts Club in Mayfair, London on Tuesday evening (11 March) surrounded by his group of giggling friends.
It was just a few hours earlier that Simon was joined by Cheryl at the venue to officially announce her return to X Factor as a judge for the upcoming eleventh series.
She left the series in 2011 to follow Simon to the US version but was rather unceremoniously sacked just a few days after starting amid rumours of concern audiences might not understand her accent.
But that's all water under the bridge now as Cheryl's said she's "thrilled" and "excited" to be on the search for talent once again.
ITV hasn't confirmed who else will be on the panel alongside Simon and Cheryl but considering Louis was out with Simon last night we imagine he's definitely in the running.
Louis famously declared last year he was leaving, then seemed to backtrack, suggesting if Simon returned, he would return.
He certainly looked happy last night… Hmm.
Also looking happy was Simon's ex-flame and close friend Sinitta, who is known for her occasional (and sometimes scantily clad – palm tree leaves, anyone?) appearances on the show.
Simon's Britain's Got Talent co-judge David Walliams and his wife Lara Stone were equally beaming as they exited the club, although, come to think of it, does David ever not look happy?!
In contrast, Simon's girlfriend Lauren Silverman looked like she wanted to keep a low profile. She did pose for a picture with the group but then hid her face once she got in the car with Simon – where it looked like the party was continuing as he grabbed a beer from a cooler.
Simon and Lauren arrived in the UK with their newborn son Eric at the weekend. Eric, named after Simon's dad, was born on Valentine's Day in New York.
Meanwhile, former Girls Aloud star Cheryl was celebrating her X Factor return in a more low-key manner, enjoying a night out with close friends including Nicola Roberts and musician Joel Compass, who got a cheeky air kiss from the star.
X Factor will return to ITV later this year.
Cheryl's X Factor highlights in pictures:
Copyright: REX/Ken McKay