A red cat fight is when two chicks, who are on the same menstruation cycle, fling period blood at each other to resolve a feminine dispute.
Dave: "Dude whats that smell? It smells like an abortion in here" Geofrey: "Bro, I know! I think my two room mates just had a red cat fight cause there's blood everywhere.
by Dildo Backpacker March 26, 2011