From TV Guide (no link):
Hilton returns to New York to host Saturday Night Live. A witness on the set reports that during the Friday night rehearsal, she refused to come out of her dressing room. She objected to a line in the opening sketch imagining her "20...30 years from now"--she didn't like the idea of being middle-aged, ever. She complained that [the sketch] included a sex tape and costarred Joey Buttafuoco.
After two hours, the sketch was killed.
When the cameras are on, Hilton pouts, preens, and doesn't screw up once. But she seems robotic, and remains that way during commercial breaks.
"Paris was one of the most self-absorbed hosts ever," the SNL source says. "She was an energy vacuum on stage, and her performance was minimally acceptable." Some cast members were so bewildered by her extreme narcissism, the source says, that they created a betting pool to see if anyone could get Hilton to ask them a friendly personal question. No one managed to collect. [...]
"I'm a sweet girl," she says in a babyish voice, looking up bashfully with her big blue eyes. "So don't be mean to me."