So there may be a small chance that Nicole Richie and Paris Hilton will find themselves face to face this weekend in Miami. Paris, who is allegedly already in town and was spotted doing what her ex BFF never does--eating at Casa Tua last Saturday, may run into Nicole, who we hear may be at Casa Casuarina on Saturday night for the after party of the MOCA Shakers Mystery Dates fundraiser along with her ex fiance, DJ AM. There's a lot of ex-ing going on here. Ex best friend, ex fiance, what next, Ex Lax? Hmmm. Also allegedly making an appearance at the former Versace mansion Saturday from midnight to two-ish is BEyonce and ex Destiny's Child, Kelly Rowland. Stay tuned.