Kelly Osbourne won't marry until her hair is long.

The 24-year-old star, who is engaged to model Luke Worrall, recently dyed her locks blonde, and has revealed her makeover is part of a promise she made her father Ozzy Osbourne about her wedding day.

She said: "There's a story behind the hair. My dad made me promise that when I got married, I'd have long blonde hair like I did when I was young. I spent three years growing my hair and dyed it blonde but it went a funny colour and all fell out. It's growing now, but I won't be getting married until it's much longer. After all, I promised my dad."

Kelly was thrilled when Luke popped the question on her last birthday, but admits she knew what he was planning.

She said: "Because he's terrible at keeping secrets, I knew he'd bought me a ring so I had a little time to prepare myself - after all, it's a really serious decision.

"I knew he was my soul mate from our first week together - I've never laughed that much in my life."