Osbourne tells Rihanna to 'get a sense of humour'

Kelly Osbourne has slammed Rihanna on twitter.

The 'Fashion Police' host appeared to suggest the 24-year-old singer should get a "sense of humour" as she defended her co-star Joan Rivers after the comedienne recently blasted Rihanna when the Bajan beauty said she still "loves" her ex-boyfriend Chris Brown.