Rita Ora's ex boyfriend Rob Kardashian has defended his tirade of accusations against the star.

The reality TV star took to Twitter in December to blast his former lover for "cheating" on him. Kardashian continued with a tirade of now-deleted posts slamming the songstress on the social networking site following their split.

In an episode of his sisters' TV show Kourtney & Kim Take Miami, Kardashian defended his actions, telling his siblings: "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.

The star added: "I don't want people to think I'm being a bitch."

Sister Khloe also spoke about her brother's relationship with Ora on the show.

She explained: "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. Because she's in the entertainment industry, she wanted to present herself to the world as a single girl.

The X Factor USA co-host added: "I think Rob got really depressed through this relationship."