The Hilton sisters caused a scene in vegas when Paris boyfriend was told her could not party with them since he is only 19. Las Vegas gossip columnist Norm Clarke reports [1]:

...their massive entourage arrived at Pure, a Ceasars Palace nightclub, at around 3:30AM. The underage shipping heir reportedly flashed a fake ID in order to join a bash that was being thrown by Paris' sister Nicky, but was summarily turned away. Clarke says Paris and Nicky had a hissy fit and left.

The group ended up at Body English at the Hard Rock. I guess they like serving to underage men like Stavros. Also apparently the girls went to apologize to the folks at Pure for their temper tantrums the next day.

[1]

JJB [2]