In fact, the reality star calls her ex "the biggest piece of s––" in a Tweet she posted Monday as part of an online rant that included accusations he was "trying to get back w/ me" while sleeping with "100's of girls."
Osbourne even posted an warning: "All he did was use me," she said, "all girls beware!"
Worrall, a British model, responded Tuesday, saying simply, "lies on twitter awesome."
The couple called off their engagement in July amid reports Worrall, 21, had cheated on Osbourne, 26. They first became engaged in November 2008.
Her Tweet barrage seemingly began on Christmas when Osbourne Tweeted she had "just found something out that has hurt my feelings so bad."
The Tweets continued the next day: "I think the best part of this situation is that I have been painted out 2 be the crazy 1 when all I did was tell the honest to gods truth," she wrote. "Thank god for family that's all I have to say."
But – to the contrary – she continued to post angry messages.
"He used me for my money and a free ride he is lucky I am not spilling the hole truth about what he did!" she Tweeted Monday. "He is the worst thing that ever happened to me ... darling ur pretty face will only get you so far because u don't have the brains to back it up."
But on Tuesday morning, the former Dancing with the Stars finalist changed her routine, saying she "felt so stupid" and was "going to be off Twitter for a while."