Spears, who is currently dating David Lucado, has made the revelation in her documentary "I Am Britney Jean", which aired in the US recently, reports femalefirst.co.uk.
"I love sex. I think sex is great. But I feel a little different about it now that I'm older. Sometimes I feel like I'm 20 and then sometimes I feel like I'm 50," she said. She has sons Sean Preston, eight, and Jayden James, seven, with ex-husband Kevin Federline. She recently also said that she was keen to add to her brood, and that now she wants a baby girl.