Britney Spears wears mini shorts to ''clean the house in''.

The 36-year-old pop superstar is famous for her extravagant stage outfits, going through seven costume changes during her 'Piece of Me' Las Vegas concert residency, but when she's at home she's at her happiest when she's in her athleisure clothes.

Britney even wears her gym gear when she's doing her chores such as cleaning up after her two sons Sean, 12, and 11-year-old Jayden - whom she shares with ex-husband Kevin Federline.

Speaking about the item she would never get rid of from her wardrobe, she said: ''I like shorts. I've always been a shorts girl, I used to play basketball, so I like mini shorts and a tank top or a cool T-shirt. That's what I clean my house in!''

Britney - who is dating her trainer Sam Asghari - has also revealed that her ideal date night outfit would be a ''classic'' staple such as a little black dress.

She added: ''I like just a classic black dress. I think you can't lose with that, when you go out somewhere, just a nice, simple classic black dress is really cute and pretty.''

And Britney likes to post videos of her working on her toned body but says she makes sure she indulges herself with whatever food she is craving, to stop her from turning into a hungry ''devil''.

She told PEOPLE: ''When I'm hungry, it's like 'Don't talk to me!' I am the devil. I am so moody. I'm a bitch! I want a hamburger and I want it now! I love food so much.

''I don't work out that much to be totally honest with you, I like to dance and I like yoga. I found a really good teacher. I think yoga is about finding the right teacher, so I can really get into that.''