Hard times for Paris Hilton and Stavros Niarchos III

When Paris Hilton first began dating Stavros Niarchos III, Mary-Kate Olsen’s ex, you couldn’t escape them. There were pictures of them driving, relaxing on the beach and hanging out at clubs. Lately, however, the camera-friendly couple has been making only sporadic public appearances. Could they be on the rocks?

At a party for Escada last week, the couple was seen brawling. "They fought all night," said one event attendee. Paris and Stavros argued in Las Vegas earlier this month at the opening of Jet. One witness told People magazine that they heard the heiress shouting to her boyfriend over the phone, "I hate you!" Says the Las Vegas Review-Journal, Stavros was upset that Paris was hanging out with Rick Salomon, her ex with whom she filmed her infamous sex tape.

But Rick isn’t the only one coming in between Paris and Stavros. His family isn’t too pleased with the relationship and has issued him an ultimatum says In Touch. If Stavros doesn’t dump Paris by the time he turns 21 - a date that’s rapidly approaching - they will take away his inheritance. Ooh. Harsh.