Chris Brown followed up date night with Rihanna by making the biggest "no-duh" announcement -- he's breaking up with his other GF, Karrueche. Chris still won't cop to dating RiRi, but is ANYONE buying his "just friends" comment? Plus, Joanna Krupa from 'Housewives of Miami' joins us to say ... she's no hooker, but she thinks she knows who started the rumor. Will JK sue, and why's she so pissed about her alleged $10,000 escort fee? Also, Nicki Minaj vs. Mariah Carey explodes again! Is Mariah smart to beef up her security -- or is it a classic overreacting-diva move? Everyone's choosing sides in the "American Idol" war.