Rihanna is showing off her killer curves on the cover of Australia's Cleo magazine.

The 23-year-old beauty is opening up about friend Katy Perry's husband Russell Brand ... and how she wasn't a fan upon first meeting the comedian.

RiRi tells the mag:

    “I first met him when he was interviewing me on TV. I was sick and it was the worst interview I’ve ever done. I was throwing up in a bucket and a doctor gave me a shot in my butt. Nothing was funny to me. I thought it was the most stupid f***ing interview I ever did in my f***ing life. Why am I talking to this idiot? He made me want to throw up again."

After the not-so-great encounter, Rihanna says she has since had a change of heart about her thoughts towards Russell. Find out what she said about him now ... after the jump.