Rob Kardashian's weight gain has only been a big issue in the Kardashian family but as well as to the many fans of the reality family and of their reality show, "Keeping Up With The Kardashians."

On last Sunday's episode of "KUWTK," Rob Kardashian's weight gain was once again the main topic momager Kris Jenner couldn't help but talk and cry about.

While the family may be having a blast in their Thailand vacation, Kris took some time to share her thoughts to second daughter Kim Kardashian about her fears for Rob Kardashian's weight gain.

"Sometimes you just want to fix Rob and you just can't. I have not, not cried myself to sleep in so long, I don't even know what that's like," the matriarch confessed of her desire to fix Rob Kardashian's weight gain issue.

Then, she tearfully continued to gush about the weight gain issue, saying, "I go to bed every night worried about him. It's like the worst feeling in the world when one of your kids isn't in a good place. You don't think its torture for me to be here in Thailand and have him at home?!"

It can be noted that Rob Kardashian's weight gain strained his relationship with sister Kim Kardashian after he ditched her wedding to Kanye West over the weight struggle issue.

Back in May, Rob Kardashian's weight gain also made headlines when his bashers poked fun of his weight on Twitter.

Kris' only son managed to hit back at his bashers by tweeting, "To the blogs saying I went to fat camp or rehab, LOL ... Then why am I still fat u fools?? Y'all must have run out of real news. First, I don't believe in rehab or therapy or anything of that sort and second, I'm a grown man and will work on myself when I choose. I'm aware that I'm fat that def ain't a surprise to me lol... My only therapy will be in the gym, anyways had to say somethingggggggggg."

In June, Kris expressed her desire to put Rob Kardashian on The Biggest Loser just so he could lose some weight and be healthy again.

Nevertheless, despite of Rob Kardashian's weight gain becoming a huge issue, Kris recently gave her son a big nod for his work.

On Monday, she took to Twitter to share to her 3.7 million followers how proud she is of her son.

"So proud of you @robkardashian!" the momager who was spotted at high-end department store Neiman Marcus wrote that day.

Sources said she saw the products of Rob Kardashian's child's sock company on display, prompting feelings and emotions of a proud mother.

"Love shopping @NeimanMarcus & seeing the new @ArthurGeorgeSocks Pre-Fall men's couture collectioN!" Kris added.