Diem Brown and Chris "CT" Tamburello TV personalities Chris "CT" Tamburello and Diem Brown appear on MTV's "The Challenge: Rivals II" final episode and reunion party at Chelsea Studio on Sept. 25, 2013 in New York City. Diem Brown died on Nov. 14, 2014, at a long battle with cancer. Photo: Mike Coppola/Getty Images

Before Diem Brown passed away earlier this month, rumors began to fly that the longtime MTV star was once again dating her “The Challenge” co-star and on-again, off-again boyfriend Chris “CT” Tamburello. While her friend Alicia Quarles denied the romance following her death, one source “close” to the late reality-TV star is now saying their relationship was more serious than Quarles let on.

Us Weekly is reporting that CT, 34, proposed to Diem, 32, "down on bended knee" while she was receiving treatment at NYU Langone Medical Center in New York for liver, lymph node, stomach and colon cancer earlier this month. According to the magazine, the marriage proposal came just five days before she succumbed to her decade-long battle with the deadly disease Nov. 14.

Unfortunately for CT, who was reportedly filming the proposal with a GoPro camera, Diem is said to have refused his offer because of her distaste for the engagement ring's style. “Diem joked that she hated rubies and said no,” said the source. Despite CT’s returning the following day with a different ring, she still reportedly refused. “Diem knew she didn’t have much longer to live,” said the source. “And she didn’t want to be engaged under those circumstances.”

While CT has yet to address the proposal claims, he did share a photo of Diem’s memorial card, rosary beads and a ring on Instagram following her funeral at St. Francis Xavier Catholic Church in New York last Wednesday. “Our plan to be together forever hasn't changed. ... It's just going to take a little longer now,” reads the photo’s caption. “And I'm going to hold onto this ring for you till we are together again. … You are The Love of My Life. My reason to be a better man. I Love You Always and Forever.”

The Ashley’s Reality Roundup was the first to report that Diem and CT had been an item prior to her passing. The duo had been together for "some time," the site claimed, and had even co-starred as partners on MTV’s “Battle of the Exes 2,” which filmed in Panama over the summer.

People magazine responded to the dating claims, saying that while Brown “had a connection” with CT, she was single when she died. “Diem had such a big heart and she had room to love a lot of people,” Diem’s longtime friend Quarles said. “And he was one of them.”