Former "KUWTK" star Rob Kardashian has allegedly lashed out against Kris Jenner after her latest attempt to mend fences with his son who's battling weight gain.

According to the report from Radar Online, Rob Kardashian is allegedly keen on keeping Kris Jenner away from him.

"When momager Kris Jenner recently reached out to her son, a new report claims the 27-year-old wanted nothing to do with her," the tabloid said.

A source allegedly told Radar Online that "Kris was always focused on the girls. It always bothered him, and he filled the pain with drugs and alcohol."

"Kris offered Rob a place to live and wanted to work on their relationship, but he turned the other cheek and is living with his sister Khloé," the source added.

"He told her that it's too late to act like a mom," the source revealed about Rob Kardashian and Kris Jenner.

After his weight gain, Rob Kardashian dropped out of "KUWTK" and shied away from the public. He is presently living with Khloe Kardashian.

"Khloe has that motherly instinct," the report said. "She's everyone's go-to person: Kim used to lean on Khloe, Kourtney drowns her sorrows about her relationship with Scott to Khloe, and even Kendall and Kylie turn to Khloe for advice."

"He's gained a lot of weight, and often times he just feels down and has no drive to go to the gym - some days he can't even get out of bed...he sits at home and eats," the source added.

Recently, Rob Kardashian addressed his weight gain in a throwback photo he shared on Instagram over the weekend. The black and white shows the former "Keeping Up with the Kardashians" star flexing his bicep.

Rob Kardashian captioned the image, and directly addressing the weight gain reports in the process: "Last throwback of the day and yes I'm fat now so yall haters can literally suck d*ck."

The said throwback photo generated support from fans, who encouraged the reality star to shake off the negative vibe and be happy with himself.

One posted a comment saying: "I love you rob f**k the negative haters your still the same amazing guy."  

Another one also said: " You're still hot and foreva will be do what makes you happy."