Rita Ora Cheated on Rob Kardashian With Jonah Hill!

One person who isn't amused by Jonah Hill: Rob Kardashian. A source tells Us Weekly that Kardashian, 25, dumped singer Rita Ora because he learned she had hooked up with the actor!

"Rita spent the night with Jonah during a trip to New York," the insider says of the British "How We Do" singer and the newly-single Moneyball actor, 29. Find out how Kardashian discovered Ora's betrayal (after nearly a year of on-and-off dating) in this week's Hot Stuff video, as explained by Us Weekly Senior Editor Ian Drew and special guest, reality star Nyasha Zimucha, who's now launch a new website, embraceyourhair.com.

rita ora jonah hill
Rita Ora and Jonah Hill Dave M. Benett/Getty; Jason LaVeris/FilmMagic

Also in the roundup? More on pregnant Duchess Kate's holiday plans with Queen Elizabeth — who invited her parents in a royal first; how Melissa Gorga's new book deal will get Teresa Giudice's goat; details on Christina Aguilera's 32nd birthday bash, and more!

Watch the video now.

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!