Rob Kardashian was going through a rough time on the latest episode of Kourtney and Kim Take Miami, but things went from bad to worse when he started taking out his anger on big sister Kim.

Rob was going through his brutal break-up with British pop star Rita Ora, and turned to Kim for some help. And by “help” we mean Rob asked Kim to ask her boyfriend Kanye West to record a song with a friend of his (who may or may not be a girl he hooked up with). Classy move, bro.

When Kim understandably turned him down, Rob lost his mind a little bit and lashed out.

“I hope your sex tape haunts you for the rest of your life,” Kim read in a text message from Rob. “And I'm going to publicly bash you and Kanye."

Whoa! If you think that reaction was a little uncalled for, don’t worry, so did Rob. He later realized the error of his ways and called his sister to apologize for saying such horrible things, “Just because I was being mean and angry.”

That's more like it, Rob! Kim thanked him for the apology, and the sibs patched things up. It's a good thing too: With everything the Kardashian kids have going on these days, they need to have one another's back!