Britney Spears -- I LOVE SEX, But ...

Britney Spears admits ... she ain't exactly the sexual dynamo she used to be back in her "I'm a Slave for U" days ... but the 32-year-old says she still LOVES to get down.

Spears confessed her love of coitus during an interview for her documentary, "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 comment, considering Britney has been very outspoken about wanting to tone down her sexuality. She recently said she was being pushed too far sexually in her music videos and in the "Britney Jean" doc, she implied her most sexually charged concert performances are behind her.

Still, Britney insists she's all about bangin' ... so, congrats David Lucado.