Mark Pincus, the billionaire Zynga founder and early Facebook and Twitter investor, is embroiled in what could be a wildly expensive Silicon Valley divorce.

His beautiful wife, Alison Gelb Pincus, the co-founder of One Kings Lane, which sold to Bed Bath & Beyond for $30 million last year, has filed for divorce in San Francisco, citing “irreconcilable differences,” and is asking the court to nullify their prenup.

The tech power couple has been married for nearly nine years and has three young children. Mark founded Zynga in 2007, a year before they married in 2008. Within four years, Zynga grew to a $1 billion company. He is now worth $1.28 billion.

A source close to the couple said, “They separated this month and divorce paperwork was filed a few weeks ago. They are seeking joint custody of their three children, twin girls and a boy.” They lived in the ultra-exclusive Pacific Heights neighborhood, home to Silicon Valley’s elite.

The divorce paperwork also reveals that Alison, 42, plans to challenge the prenup, given that his net worth skyrocketed during their marriage. Another source adds that Mark, 51, was already wealthy going into their union. Despite this, the papers filed with San Francisco County Superior Court reveal he isn’t willing to pay her attorney fees.

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