"His mother's passing was extremely hard – that's when I developed a friendship with Sean," Boone explained.
Sean was living in Texas in an apartment by himself up until his passing. As RadarOnline.com reported, he was admitted to a hospital last week after having complications from an undisclosed infection. He ultimately passed away on Sunday, Feb. 17.
According to Boone, Sean relied heavily on his mother before her passing. The once-900 lb. reality star was often assisted by Renee on the show.
"He was wheelchair bound and couldn't move around much," Boone said.
"I think it changed him because he had to become independent which he'd never been before," Boone said of the effect Renee's passing had on the star.
Boone said she would help Sean with tasks around his apartment, such as helping him "pack and sort boxes for donation."
Sean's friend added that he also struggled to afford to live on his own as he relied on his social security.
Sean's father wrote a touching tribute to his son on Facebook following his death.
"As most of you know he was in Houston, Texas to be a part of his long struggle with his weight," Matt Milliken wrote on Facebook. "Today he lost the battle, but is now free to be with his mom, Renee M. Milliken. I'm sure she was waiting for his return home to be with the Lord and her."
"They are both at peace now; in my mind a lot better place without the struggles we have with our bodies on earth!" he added.
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