Paris Hilton in Court

A friend of Paris Hilton's new boyfriend Stavros Niarchos has reportedly launched a lawsuit to stop the hotel heiress from speaking about him negatively. Brian Quintana has served Hilton's legal representatives with a "cease and desist" letter which contends that she is "ruining his reputation and interfering with his business relationships," according to PageSix.com. Quintana's legal papers read: "We would expect Ms. Hilton to understand the danger of making false statements against others." The Los Angeles party planner claims his feud with Hilton reached a head during an American Music Awards after-party when she allegedly requested security to remove Niarchos' friends from L.A.'s Club Privilege.