The reality star turned against his own sister when she offered him advice about his bitter split from singer Rita Ora - which resulted in a public twitter feud last December during which Rob accused the British beauty of cheating with over 20 men - in the episode of 'Kourtney & Kim Take Miami' which aired on Sunday night (17.02.13).
Speaking to her mother Kris Jenner on the phone, Kim explained Rob had asked her whether her rap mogul boyfriend Kanye would team up with his friend on a song, a request which she refused.
Kim revealed: ''He said, 'I hope your sex tape haunts you for the rest of your life and I'm going to publicly bash you and Kanye.' ''
Moody Rob took offence to his sister's meddling after she accused him of being too public about his feelings and flirting with the wrong kind of girls in order to get over his heartbreak.
However, Rob later called the 34-year-old Armenian beauty up to apologise and said: ''I wanted to apologise. Obviously the things I said to you in the text message, I was just being mean.''
Kim replied: ''I appreciate you being mature and calling me instead of dragging this fight out.''
The mother-to-be - who is expecting her first child with boyfriend Kanye West - admitted she was glad he had split from 'How We Do' singer Rita as she worried he was making the same mistake she did with her ex-boyfriend Kris Humphries - who she filed for divorce from after just 72 days.
She said: ''When I was in my last relationship I clearly wasn't happy. Khloe called me out on it all the time, I don't want you to be taken advantage of by the lame girls out here.''