Paris Hilton's boyfriend CY WAITS was left red-faced as he watched the socialite chat to U.S. late show host David Letterman on her 30th birthday (17Feb11) - when the cheeky TV personality quizzed her about her fragrance line.
Former club boss Waits was watching the show from the hospitality lounge as Hilton chatted about her 11 scents, including cologne Just Me For Men.
Letterman asked, "Seriously, what kind of a man buys Just Me For Men?"
Waits then appeared on screen and didn't seem too pleased about the joke.
The host added, "It looks like he's ready to come out here."
Earlier on during the chat with Hilton, the socialite unveiled her new iPhone application, which allows fans to add a picture of Paris to snapshots of themselves.
She took a picture of Letterman and added in a posed shot of herself, which thrilled the host.
He said, "I wonder what the boyfriend thinks of this shot. Happy birthday."
The camera panned to Waits in the wings, who smiled awkwardly and gave Letterman the thumbs up.
At the end of the interview, Letterman presented his guest with a bouquet of roses, joking, "Mr. Big Shot is back there in his Member's Only jacket, but look what I have for you."