Kelly Osbourne has sparked rumors she is engaged.

The 23-year-old star - who shot to fame on fly-on-the-wall MTV show 'The Osbournes' with her rock star dad Ozzy, mother Sharon and brother Jack - was spotted wearing an diamond ring on her engagement finger.).

Kelly and 18-year-old model Luke Worrall, who have only been dating for four months, were enjoying a romantic evening in London when she began waving the impressive band around to a crowd of photographers.

The loved-up couple couldn’t keep their hands off each other as they dined at Japanese restaurant Nobu in London’s exclusive Mayfair district.

They then partied at the Bungalow 8 nightclub with a group of friends including Kelly’s brother Jack and model Kimberley Stewart.

Her spokesperson said: "No, she's not engaged. The ring was actually a present from her dad Ozzy."

Image WENN