Rihanna and Joan Rivers are at war!
The 79-year-old E! Fashion Police host called the 24-year-old "We Found Love" singer an "idiot" Friday after watching her open up about ex Chris Brown, 23, with Oprah Winfrey -- and Rihanna fired back.
"Rihanna confessed to Oprah Winfrey that she still loves Chris Brown," Rivers tweeted. "Idiot! Now it's my turn to slap her."
Rihanna quickly responded, "Wow, you really do get slow when you're old, huh?" But it appears she has since deleted the tweet.
In candid interview with Winfrey on Oprah's Next Chapter on Sunday, Rihanna said she still has feelings for ex Brown -- even after he was arrested for physically assaulting her in February 2009.
"We love each other and we probably always will, and that's not anything that we're going to try to change," Rihanna told Winfrey, 58. "I think he was the love of my life. He was my first love and I see that he loved me the same way. I truly love him. The main thing for me is he's at peace. I'm not at peace if he's not happy or he's still lonely. I care. It actually matters that he finds that peace."
Whether Rihanna wanted it or not, Rivers offered her a piece of advice on Twitter. "Honey, Rihanna, everyone knows: If he hit you once, he'll hit you again. Read the statistics," Rivers warned. "PS -- Love to have you on Fashion Police!"