Her Opponent: Ciara
Why They Were Beefing: During an episode of E!'s Fashion Police, Ci-Ci was chatting with Joan Rivers and stylist George Kotsiopoulos when Rihanna's name came up. And Ciara didn't seem to have anything nice to say about her. "Rihanna used to be so nice," she said. "I just saw her and she wasn't the nicest." That led to a Twitter spat between the two, which included barbs like, "My bad ci, did I 4get to tip u? #howrudeofme" (from Rihanna to Ciara) and "Trust me Rihanna u dont want to see me on or off the stage" (from Ciara to Rihanna).
The Result: To be honest, we're not sure. It seems like they patched things up after their short scuffle—albeit on Twitter—but don't hold your breath if you're hoping they'll perform or record together in the near future