Paris Hilton is not a happy heiress after a weekend appearance on the Late Show with David Letterman, which saw the host harass Hilton over her time in jail.

The 26-year-old reality star agreed to appear on the show to promote her new perfume and fashion line, but instead suffered a barrage of questions about her time in jail.

After initially greeting Hilton, Letterman asked, "How'd you like your time in jail?"

A visibly-uncomfortable Hilton replied, "Not too much."

As Letterman continued to question the former jailbird, Hilton grew increasingly annoyed, pouting and looking off-stage for help.

"I've moved on with my life so I don't really want to talk about it anymore" Hilton told the host but Letterman would not be dissuaded.

"This is where you and I are different. Because this is all I want to talk about," he said.

Towards the end of the interview, Hilton told Letterman he was making her sad for coming on the show and "hurting my feelings".

Letterman tried to cheer the heiress up by joking, "I'll buy you a parakeet!"

The interview will screen in New Zealand on Prime TV tomorrow night, at 11.05pm.