Gavin Rossdale 'was cheating on Gwen Stefani with their family nanny for 3 years' - new reports claims

According to a new report by Us Weekly magazine, Gavin Rossdale cheated on wife Gwen Stefani with their family nanny for three years. Their report below...

"It was a very unhappy ending for Gwen Stefani and Gavin Rossdale. Insiders exclusively reveal that the music super couple’s 13-year marriage ended because of adultery: Rossdale’s three-year relationship with the family’s longtime nanny, Mindy Mann.

Back in February, Stefani, 46, uncovered Rossdale’s long-term affair with Mann, who cared for the couple’s three sons, Kingston, 9, Zuma, 7, and Apollo, 20 months.

At the time, the No Doubt frontwoman discovered explicit texts between Rossdale and the nanny — including nude photos of Mann and their plans to meet up for sex — on the family’s iPad.

“The iPad was linked to Gavin’s phone,” a family source tells Us. “One of the other nannies discovered the exchange and told Gwen.”

Mann was soon fired, but the Bush rocker, 50, insisted to Stefani that the exchange was simply “flirtation,” one source explains. When he finally confessed to the affair months later, the “Used to Love You” singer made the decision to end their marriage. The couple announced their plans to divorce in August.

The sexual relationship lasted for more than three years -- including the time period when Stefani was pregnant with Apollo.

"This was done right under Gwen’s nose,” a source tells Us.