Britney Spears revealed some of her more personal side during her I Am Britney Jean documentary, which aired on E! on Sunday night.

The “Work Bitch” singer, 31, talked openly about sex but how it’s changed for her since growing up and becoming a mom to Sean, 8, and Jayden, 7.

"I love sex. I think sex is great, but I feel a little different about it now that I am older,” she said in the documentary. She later said, "Sometimes I feel like I am 20 and sometimes I feel like I am 50."

Entertainmentwise notes there’s a part where Spears doesn’t want to kiss her male co-star for her “Perfume” video in front of her dad, Jamie Spears.

Her longtime manager, Larry Rudolph, comes to her rescue. "She doesn’t like shooting these kind of scenes with him around so I have to be the one to deliver the bad news to him, that’s he’s got to…adios,” Rudolph tells the camera before letting Jamie know.

Jamie obliges, but not before teasing her a little by kissing the window of the car she’s sitting in.

The documentary also shows a glimpse of Spears' relationship with her boyfriend, David Lucado.

image: NBC