The 32-year-old pop star made the stunt as a part of ITV's 'Surprise Surprise' Christmas special which aired on December 18, reported E!Online.
The fan, James Calhoun, was nominated by his sister Sadie for his continuous support after she welcomed premature twins.
"He gave up his spare time and cared for the boys as if they were his own - I could not have done it without him," Sadie said.
"I know what a special uncle and brother Jim has been, and I know he's my number one fan," Britney said.