The `California King Bed` singer - whose close friend Katy Perry is married to the British comedian - did not like him when they first met because she was ill and didn`t think he was "funny".
She said: "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."
However, the 23-year-old beauty changed her mind about Russell when she met him the second time, admitting she was probably "a complete bitch".
She told Australia`s Cleo magazine: "We did another interview on MTV and I realised he was funny. I was probably a complete bitch, but only months afterwards did I get it."
Despite being close friends with `Firework` hitmaker Katy, Rihanna was not able to go to India to her wedding to Russell in October last year, something she has previously confessed regret about.
She said: "I will never ever forgive myself for that, it was a crazy time, it was a crazy week, I`m switching management. There was no phone service in India and very little-to-no internet service, so it would have been a little irresponsible of me. I`m sad that I missed it."