The lovey-dovey twosome, dating for about a year, have been repeatedly photographed locking lips while Hilton travels to promote her new iPhone app. (The Ministry has discovered that the completely gratuitous app inserts the heiress into photos, tells you if you're "hot or not" and provides news and quizzes about Paris. Not sure if that's fab or frightening.)
Love has been on the celebutante's mind. When David Letterman asked her what was missing in the lives of Charlie Sheen and Lindsay Lohan -- who like Paris have had their share of run-ins with the law -- she said "true love."
Barf. Watch the hilarious full interview after the jump.
She also told the prickly host that she plans to start a family in the next decade that will amount to three or four kids.
It's pretty obvious she's smitten with Waits, 35, who waited (im)patiently for her backstage at the "Late Show" and planned her Moulin Rouge-themed 30th birthday party. He also bought her a Lexus LFA -- and the spending spree didn't stop there.
"They shopped for engagement rings," a source told People. "They were really cute together. Paris was making comments about the rings and joking that her ring has to be at least 24 carats."
But Hilton and Waits left the luxury Jacobs & Co. with a different kind of ring: a $25,000 white gold and black diamond encrusted bauble. Not too shabby, eh?
Her rep told the mag that they were shopping for "something special" for her birthday. We guess the Lexus wasn't enough. Maybe he was trying to make up for the stolen $3,200 absinthe-laced cake?
The tiny-dog-toting Hilton, currently on probation after pleading guilty to obstruction and cocaine possession, celebrated her big day multiple times in multiple cities, including Los Angeles and New York.
But it isn't all Champagne kisses and caviar dreams for these lovebirds.
Waits has an Aug. 22 court date to face felony criminal charges stemming from a traffic stop in which police reported a "vapor trail" of marijuana wafting from the couple's black Cadillac Escalade. That same traffic stop landed Hilton in trouble as well.
He was subsequently dropped as managing partner at Wynn and Encore's Tryst and XS nightclubs because of the charges. No wonder his loving lover plugged his new company on Letterman.
You know what they say: The couple that allegedly breaks the law together stays together. Best wishes, kiddos.
-- Nardine Saad
Photo: Paris Hilton and Cy Waits arrive at her 30th birthday party at LAVO in New York on Feb. 17, 2011. Credit: Evan Agostini / Associated Press