Scheana Shay is opening up about a dark time in her marriage.

The Vanderpump Rules alum revealed that her husband Brock Davies had an affair while she was pregnant with their daughter Summer Moon, now 4, in 2020.

According to the "Good as Gold" singer, Brock confessed to cheating amid the media frenzy of Scandoval—a.k.a. her costar Tom Sandoval's 2023 cheating scandal with Rachel "Raquel" Leviss.

"I had spent so much time fighting off my anxiety and convincing myself that just because Tom cheated on Ariana [Madix] didn’t mean Brock would ever cheat on me," Scheana wrote in an excerpt from her new memoir My Good Side published by Glamour magazine on July 10. "Now I was finding out just how wrong I was."

Scheana explained that the Australian athlete—whom she married in 2021—came clean amid rumors he had sex with a San Diego woman he knew from before their 2019 meeting.

"As I sat there, feeling completely sick to my stomach, he admitted that—at the time—he was scared about being a father again, specifically about whether he even deserved to be, and he chose to deal with it by sleeping with someone else," the 40-year-old recounted. "I use the word 'chose' because it was very much a conscious decision. No one twisted his arm or dragged him into bed."

At first, Scheana couldn't imagine that Brock—who is also dad to two kids from a previous relationship who live in Australia with their mom—would betray her while she was expecting their first child together.

"I didn’t want to believe what he was telling me, and, oddly, I didn’t know how to react, either," she continued. "I was so angry, so sad, and so hurt; those were givens."

So, Scheana "started pacing back and forth, fuming, and feeling like I might throw up," she wrote. "Then, unable to contain my rage, I slapped him and threw a Rubik’s cube in his direction, which he dodged. To this day, every time I see a Rubik’s cube it triggers me, pulling me right back to this incredibly dark moment in my life."

As for how the extramarital affair started, the Bravolebrity recounted, "One day, while I was at home, pregnant with his child, Brock went to work at his gym, F45 Training East Hillcrest in San Diego, and he ran into her outside. After reconnecting, he said they began a brief affair."

However, Brock later realized he didn't want to put his new family in jeopardy and wrote Scheana a letter apologizing for his transgressions.

"He said he realized he was throwing his second chance at a family away by stepping out and swore to himself that he would never betray me again," she shared. "He also pointed out that it was purely physical, never emotional, and he always used protection."

"Once I’d read it, that was more than enough," Scheana concluded. "I told him to immediately toss it into the fire. I never wanted to set eyes on those words again."

Read more juicy stories from Scheana when My Good Side comes out July 22 anywhere books are sold.

In the meantime, keep reading to look back at her and Brock's family photos with daughter Summer Moon.

Baby Summer Moon and Scheana Shay enjoy some fun in the sun.

Brock Davies and Summer match in their blue and white Chargers jerseys.

THe family of three look adorable in costumes during Summer's Monsters, Inc.-themed second birthday in April 2023.

"Growing up, my family threw a big luau every year," the "Good as Gold" singer revealed in May 2024 during a family reunion. "My parents got engaged at one, people even got married at them!! After my grandparents passed away, we stopped but 22 years later we finally brought it back!"

"Thanks to the two of you, I get to celebrate today!" Scheana shared on Instagram. "@brock you made me a mother. Something I didn’t know was possible. @summermoon you chose me to be your mommy and my world is now complete. You are the most incredible human who’s so kind, empathetic, smart and beautiful inside and out. I’m so proud everyday to be your mom! Happy Mothers Day to all of the mamas out there and to everyone who has lost their moms, just remember they are always with you looking down and so proud of you!"

"Happy Father’s Day to the most incredible man!" Scheana wrote in June 2024. "@brock you show me every single day what an amazing dad you are to Summer and we are SO lucky to have you. Thank you for everything you do for us. we love you!!!"

Brock honored Summer's special bond with Lala Kent's daughter Ocean, writing, "Growing up, I went to 15 schools in 12 years. At the age of 4 I lost 1 1/2 fingers in a farming accident. I suffered a lot from bullying and a learning disability. I dreaded school, and I struggled in class.Thank you @lalakent for this friendship, it’s bigger than us."

Scheana, Brock and Summer reunite with costar Lala, her daughter Ocean and VRR alums Jax Taylor and Brittany Cartwright, with their son Cruz, at the Hot Wheels: Ultimate Challenge premiere in L.A.

Scheana and her mini-me flash adorable grins.

The couple celebrate Summer's first dance recital.

The mommy-daughter duo enjoy a Chargers game with Lala.

"They call me Mummy," Scheana wrote on Instagram of their matching costumes.

Summer meets Santa Claus in December 2023.

"Merry Christmas from the Davies family!" Scheana shared.

Scheana and Summer twin in their winter gear.

"You are enough, my love @scheana," Brock wrote on Mother's Day 2024. "You are amazing with @summermoon. The love you show her and myself makes every day special #happymonthersday."

(E! and Bravo are both part of the NBCUniversal family)

Check out Peacock to binge your favorite NBCU TV shows and movies, live sports and more!