Nicole Richie and Paris Hilton shared a laugh at a party to celebrate the launch of Charlotte Ronson's latest I Heart Ronson line for JC Penny at the Roosevelt hotel in LA last night. The former The Simple Life costars are rarely photographed together in recent years, though this makes two nights in a row for Paris and Nicole as they both attended the Britney Spears concert on Monday as well. Paris even tweeted to Nicole after the bash using their cutesy nicknames for each other, saying, "Bill, great seeing you tonight at #Iheartronson. You looked so beautiful! Love you. Love Sill xoxo." Paris was home in time to watch herself on Lopez Tonight, and overall she seemed to be in good spirits despite confirming her split from boyfriend Cy Waits earlier in the day. Ashlee Simpson also attended last night's soiree amid her own love life rumors. Ashlee Simpson was spotted kissing Vincent Piazza and holding hands with the Boardwalk Empire star during an outing in NYC last week.