We thought this one would last.
E! News has confirmed that Nicky Hilton and her seemingly rock-solid longtime love, David Katzenberg, have called it quits after a whopping four years together.
So what happened to the lovebirds?
"There was no drama," a source close to the newly single heiress told E! News. "They started dating when they were very young. Travel and work schedules left them little time to spend together."
In fact, this breakup was so amicable that Paris' little sis was even spotted at a Lia Sophia jewelry launch Wednesday night with David's twin sister Laura, who she still counts as one of her best friends.
Now that's keeping it classy.
As for those scheduling conflicts...Nicky is heavily involved with work on her fashion business and was constantly traveling overseas to promote her jewelry line, leaving little time, it would seem, for her man.
David, meanwhile, is no professional slouch himself, as the son of Dreamworks honcho Jeffrey Katzenberg has followed in the family's footsteps and begun his own production company. His biggest credit is creating the MTV show The Hard Times of RJ Berger and he's currently working on another show for the network.