Tina Knowles Opens Up About the Infidelity in Her Marriage to Mathew Knowles

Fourteen years ago Tina and Mathew Knowles settled their divorce after a messy outside baby scandal [click here if you missed that]. 

In her new memoir 'Matriarch' Tina breaks her silence on the decades of cheating that led to the end of her 31-year marriage...

From People

"There were already problems in our marriage that first year," writes Knowles, who details how Mathew had a continuous problem with fidelity. "But the suspicions I had would get washed away by the fact that our love was stronger than a misstep...It was us against the world, taking on what life brought us."

Knowles goes on to share that once, when she was pregnant with Solange, she reached a breaking point.

"The marriage was deteriorating faster than I could possibly find ways or even reasons to make it work — even with the pregnancy," she writes. According to Knowles, her husband became more reckless and she contemplated leaving. "I had gotten used to these extremes — incredibly joyous half the time as we shared life’s adventure, then being disgusted and heartsick over how brazen his cheating could get."

But the two found perfect harmony when it came to helping their daughters reach stardom. A skilled hairstylist and fashion designer, Knowles spent most of the 2000s behind the scenes creating avant garde looks for the Beyoncé-fronted super group Destiny’s Child, helping define the hit R&B act’s unique style, before implementing the same winning strategy for their daughters’ solo careers.

Throughout it all, the ups and downs of her marriage continued. "I was caught in this dance with him, each doing the same steps over and over: He would cheat or act up, and I would say I’d had enough. He would beg for forgiveness, crying and promising to get better... But this is what married people did, I told myself."

Then in 2009, came news that gutted her. Knowles learned through the press that her husband had fathered a child outside of their marriage. When he tried to speak with her later that day "I screamed, 'Get out! Get out!' like he was some demon. 'I hate you!' ... my world had exploded."

After 31 years of marriage Knowles divorced Mathew in 2011. "I was deeply sad, not about him but about the marriage," she writes. "I felt like I failed. I failed us, my kids — ­myself." But, she tells PEOPLE, eventually the split set her free and on a new path.