For years, one of the most talked-about storylines in the Real Housewives world has been Mary Cosby’s marriage.
The Real Housewives of Salt Lake City cast member tied the knot with her step-grandfather, Robert Cosby Sr., a decision that even she admits was far from typical.
Recently, according to Bravo's The Daily Dish, she opened up about how it all happened and why she chose to follow through.
Mary revisited the subject while walking through the newly renovated Faith Temple Pentecostal Church with her cousin, “Big Joe,” during Season 6. The church was founded by her grandmother, Rosemary “Mama” Cosby, and Mary explained that her grandmother’s influence shaped nearly every step of her life.
“When I was younger, I remember Mama called me and she was like, ‘Mary, I think it’s time for you to come back and be saved and get in church,’” Mary recalled. “Because of her, I am everything I am.”
When Mama Cosby passed away in 1997, her will included an unusual request. To continue her grandmother’s legacy and become the church’s first lady, Mary was expected to marry Rosemary’s husband, Robert Sr.
At the time, Robert was already in his role as bishop. “That was odd to both of us,” Mary admitted. “He obeyed what Mama wanted. He wasn’t trying to do anything extra.”
The marriage didn’t just spark confusion among outsiders. Inside the family, tensions exploded, especially with Mary’s mother, Rosalind. Mary revealed that Rosalind believed she was entitled to take over the church and even attempted to seize control of a service.
The two remained estranged for years, with Mary claiming her mother spread damaging stories about her and Robert Sr. Their relationship never healed before Rosalind died in early 2025. “It was a storm or a battle that I had been in for all those years,” Mary said, reflecting on the pain of losing her mother without reconciliation.
Through it all, Robert Sr. has remained by Mary’s side. Married since 1998, the couple leaned on each other as their son, Robert Jr., struggled with addiction. “I didn’t have a support system with him. I just had Robert Sr.,” Mary explained. “I couldn’t have done it without him.”