AceShowbiz -

The third person in Rita Ora and Rob Kardashian's relationship has been identified. Turns out Kardashian found out that Ora was cheating on him with "Moneyball" star Jonah Hill and then dumped her.

"Rita spent the night with Jonah during a trip to New York," a source told Us Weekly. Ora and Hill allegedly met a club in the city in November and left the place together. "I heard she cheated, but I don't know," reality star Nyasha Zimucha said in a video for Us Weekly.

Kardashian previously accused Ora of cheating on him with as many as 20 men. "She cheated on me with nearly 20 dudes while we were together, I wonder how many she will sleep with now that we apart? But I mean 20?!!!," Kardashian tweeted. "How can a woman who is so busy trying to start her own career have time to be with so many dudes all while in a relationship?!"

However, Ora cleared up the smoke on her relationship with Kardashian. "I'm not going out with Rob," she said. "We were close for a while, but it didn't work because I was never there. I was like a ghost. I used to get so frustrated with myself and then wonder why I was angry, so I decided it was best to keep it friendly, especially at the moment, when there's so much going on."

Kardashian later confirmed that he is back single, telling Ryan Seacrest, "I'm very, very single. I'm very, very happy. For the first time in a long time, so it's a good thing. Honestly, it's all about working out in the new year and businesses. This is just the beginning."