Christine Quinn missed the 'Selling Sunset' reunion after testing positive for COVID-19.

Christine Quinn tested positive for COVID

Christine Quinn tested positive for COVID

The 33-year-old star was keen to appear on the show, but she was ultimately unable to after returning a positive test result.

A source told 'Entertainment Tonight': "The 'Selling Sunset' reunion was super heated and overall emotional.

"Christine really wanted to be there and was feeling ready to address everything head on and face the music. She was looking forward to having her moment. Unfortunately, it just boiled down to a matter of her health. She was extremely sick."

Despite this, the reunion special did feature the likes of Jason and Brett Oppenheim, Chrishell Stause, Mary Fitzgerald, Romain Bonnet, Heather Rae El Moussa, Amanza Smith, Maya Vander, Davina Potratz, and Vanessa Villela, among others.

The insider explained that the show was "very difficult" for Jason and Chrishell, in particular, following their high-profile break-up.

The source said: "They're both still very raw from their break-up and it wasn't easy reuniting. A lot happened between them and it will be discussed in great detail."

Earlier this year, Chrishell admitted her romance with Jason caught her by surprise.

The TV star also revealed how their friendship took a romantic twist.

In her memoir 'Under Construction', Chrishell writes: "One night when we were out, we kissed. What could have ended up with us laughing and saying, ‘What were we thinking?' instead kicked off my first relationship where I've felt like I can be 100 percent myself."

Chrishell also revealed how her relationship with Jason differed from her past romances.

She wrote: "There was nothing romantic between Jason and me for the longest time. Through working with him every day, I developed a huge amount of respect for him.

"Jason was there for every break-up I had, and every bad day, and we became close through all those conversations. He became my best friend. I also never tried to impress him, except maybe for closing deals at work. Talking to Jason became comfortable and comforting."