Kelly Brook says fighting with fiancé Billy Zane boosts their sex life.

The sexy star keeps the passion alive with the Titanic actor by arguing with him as much as possible and keeping the lights dimmed in their bedroom.

Kelly said: "Couples should fight a lot. Even if you do agree, pretend you don't.

"I'm a brat for the sake of causing trouble - but tongue-in-cheek and with a twinkle in my eye.

"It's about mentally stimulating each other as much as it is about the physical and emotional side.

"The key to a good sex life is fantastic lighting! When you redecorate make sure everything's on dimmers. Either that or candlelight."

The star of British TV dance show Strictly Come Dancing also revealed that her stunning curvy figure is all down to "having tons of sex".

She said: "My body is down to having tons of sex so I look fit and healthy - it's the best thing in the world."

The former Smallville actress insists she has to fight off lots of competition from "hotter girls" when she goes for acting roles.

She said: "I have to audition for things. They don't just hand it to me because I look hot.

"I'm 27 and there are tons of hotter girls out there who are ten years younger than me."