Kris Jenner breaks down into floods of tears on Sunday’s episode of Keeping Up With The Kardashians.

In a preview clip released, the 58-year-old mother and manager admits to Kim that she cries herself to sleep over her son Rob, 27, who is feeling depressed due to weight gain.

Kim, however, is less sympathetic and insists she doesn’t feel sorry for her younger brother and thinks he needs to stop moping and do something to improve the situation. Speaking to Kim, 33, Kris says: ‘I want to fix Rob and sometimes you just can’t.

‘I have not not cried myself to sleep in so long that I don’t even know what that’s like.  ‘It’s the worst feeling in the world when one of your kids isn’t in a good place.’ Kim - who has 13-month-old daughter North with her husband Kanye West - also acknowledges that her sister Khloe, who she says has a special bond with Rob, is also worried about him.

In the conversation with her mother, which takes place during a family holiday in Thailand, Kim says she finds it ‘frustrating’ that Khloe fretting about the Rob situation. ‘She gets anxiety with the whole Rob situation when she is away,’ Kim says. ‘She kinda wants to go home. It’s so bizarre. I just get so frustrated.’

When Kris suggests Khloe is rightfully concerned because Rob is home alone in Los Angeles, Kim interjects: ‘Well he’s not home alone, he’s also 27 years old, I just don’t see what the point is. She doesn’t need to help everyone.’ In last week’s episode, Kim said of Rob - after he failed to join the trip: ‘We’ve all been here to offer him help and he won’t take it, so I don’t have sympathy.’

She then turned to the camera and explained: ‘I think I’m just more of the tough love kind of person. My personality is like, ‘All right, you complain, you don’t like it, get up and do something about it.’’ Rob has reportedly been distant from his relatives since he refused to attend Kim and Kanye West’s wedding in May following a huge family bust-up. The footage in Thailand was filmed before Kim’s European wedding.