Oh no, not this again! Rob Kardashian explained why he trashed his "ex" Rita Ora on Twitter in December, accusing her of cheating on him with 20 dudes, while she took the high road, maintaining that they were never really a couple.

That nebulous status is addressed straight ahead and on TV no less. Come on, the Kardahians never do anything off camera.

On 'Kourtney and Kim Take Miami,' his sisters' reality show, his actions were discussed. "Rob just got out of a really weird relationship. They were actually together for about a year but Rob was never allowed to admit that they were actually an item," Khloe Kardashian said. "Because she's in the entertainment industry, she wanted to present herself to the world as a single girl."

Okay, so the Kardashian account is that it was all Rita's fault. It's understandable that the sisters want to protect and defend their brother. However, they told him not to take aim at Ora in the digital space. He ignored that advice, tweet bombed her and then deleted the offending, 140-character assaults. But not before the press got hold of it.

Rob defened that choice to accost Ora in a series of tweets, saying, "I posted what I posted to keep myself from taking her back. Every time she messed up, I took her back for over a year now. I just had to do that to make her hate me."

Again, it's all Rita Ora's fault. Khloe tried to point out that even though Ora was doing him dirty -- again, their side of the story -- his actions made him look like the jagoff.

His sister Kim, who airs her dirty laundry in public like it's her job, was actually the cooler head here. She said, "You loved her for a reason. You aren't together for a reason now. You just always have to take the high road."

Ask Kris Humphries how he feels about dat!

Watch the Rita Ora 'How We Do' Video