Britney Spears: I Love Sex ... But I'm So Old!

Britney Spears loves sex, but she feels like an old lady in the bedroom sometimes, or so the singer claims in her new documentary, "I Am Britney Jean."

A sexual dynamo who used every ounce of appeal in her arsenal to sell 50 million records, Britney's still got it nowadays ... even if she's not feelin' it.

Spears confessed her love of boning in "I Am Britney Jean," saying, "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."

It's an interesting statement, considering Britney has been outspoken about wanting to tone it down, despite admitting "a lot of sex goes into what I do."