Paris Hilton has revealed that the real reason she called off the engagement was because her fiancée Paris Latsis has cheated on her during his bachelor party.

Last week, Paris, 24, broke up with her fiancée Latsis after only five months of dating, claiming she feels she's not ready to marry.

Hilton stated at the time: "I'm sad to announce that I've called off my engagement. Over the last couple of months I've realized that this is the right decision for me. We remain best of friends, and I'll always love him. I hope people will respect my privacy during this emotional time."

But, according to close friends, the heiress of Hilton empire revealed during a party in Los Angeles that Latsis has had an affair with another woman.

When asked by America's Extra TV reporter to give some advices to a man who wants to get married, Paris said: "Be good to your girl, communicate and tell the truth. And don't cheat on her at your bachelor party."

Hilton also denied having a romantic relationship with Mary-Kate Olsen's ex-boyfriend, millionaire Stavros Niarchos III. "I'm single and loving it."