Khloé K and Kris break down in tears during family drama

This week's episode of Keeping Up With the Kardashians is set to be an emotional one, if the preview clips so far are anything to go by.

Earlier this week we saw Kim lash out at her mum Kris Jenner for mollycoddling her 28-year-old brother Rob, saying it was "pathetic" how much the family did for him, but it seems that's not the end of the drama.

In two new clips released today, both Khloé and Kris are seen separately breaking down in tears about Rob's situation.

Rob has kept a low profile in the last 18 months, having gone bankrupt, ended his relationship with singer Rita Ora and gained a significant amount of weight.

In the clip from this Sunday's episode, Rob's mum Kris Jenner bursts into tears as she discusses her fears for her son. "He's gained over 100 pounds in the last year," she says. "He's missed Christmas, he missed Kim's wedding."

Kris then goes on to admit that she fears Rob may end up risking his life if he does not make a drastic change soon.

Later in the episode, Khloé is seen shouting at her brother during an emotional phonecall, asking him to give in and accept help from his family once and for all.

"Do you think that it's fair to do this to me though? Like I've been through this how many times? I did this for years and now you're going to do this to me too again?" she asks.

Last weekend, Rob reportedly went missing for three days, not responding to family calls and staff visits to his home. Thankfully he reappeared without explanation after three days, but it's thought his family were close to calling police.

"Khloé thought they needed to call the police and file a missing persons report, but Kris didn’t think that was necessary," a source told RadarOnline. "She thought Rob would get very angry that the cops were called, and it would have created a media circus."

We hope poor Rob can work things out, for his own sake and his family's…