HOLLYWOOD, Calif. — It's over for Kelly Osbourne and fiancé Luke Worrall.

The couple has called off their engagement amid reports the British model cheated on the reality star.

"Thank you all so much for your support but the matter is private and [I] will not be commenting," Osbourne told her fans Wednesday on Twitter. "Enough damage has already [been] done!"

Osbourne, 25, and Worrall, 20, got engaged in November 2008 after six months of dating.

"We get on so well together. I really do love him," Osbourne once said of Worrall. "Every time we are in each other's company, we always have a good time."