'Real Housewives' alum Gretchen Rossi mourns death of fiance's son from cancer

"Real Housewives of Orange County" alum Gretchen Rossi is mourning the death of fiancé Slade Smiley's son Grayson Smiley-Arroyo from cancer.

"Our rational minds told us this day might come, but our hearts always held onto the hope that this day would not come to fruition," Rossi wrote in an Instagram post dated Feb. 7, sharing photos of herself and Smiley with Smiley-Arroyo throughout the years.

Rossi said she and Smiley are "beyond devastated and heartbroken" over Smiley-Arroyo's passing at 22 after a lengthy battle with cancer, calling him "such a special human being."

"He was an Angel on this earth and an incredible warrior…a warrior like no one has ever seen before. He fought everyday through his pain and discomfort to find joy in the smallest of things. He was always singing & dancing & laughing despite his circumstances," the former reality star continued. "He was a true beacon of light and hope."

Rossi said Smiley-Arroyo "made an incredible impact on so many people" despite his life being cut short, adding, "The Lord knew his life had purpose and would touch many along the way."

"We are forever grateful for the many lessons learned from this little man, and will miss his beautiful spirit immensely," she concluded the post. "May the Lord hold him in his hands, renew his broken body, and give him life again. This isn’t goodbye but rather see you soon little man…..We love you Grayson. You will forever be in our hearts."

Rossi's post garnered thoughtful messages from throughout the "Real Housewives" universe, including "RHOC" stars like Vicki Gunvalson, Heather Dubrow and Lydia McLaughlin to name a few. "Real Housewives" executive producer and reunion host Andy Cohen also sent condolences.

Smiley-Arroyo's mother Michelle Arroyo also shared a sweet post dedicated to her son in which she revealed he died Sunday night.

"I’m still in shock and going through the motions of dealing with all the details," she wrote.

"I know Gray is playing cards with Gramma and playing Trouble with our beloved Diane," she added. "His dog Mo is right at his side as he never left him."