Chris Pizzello / Invision/AP 1 / 4
Chris Pizzello / Invision/AP 1 / 4

By Michelle Lanz

With rumors aflutter that Matthew Morrison may have been (or still is?) hooking up with "Glee" costar Lea Michele, the star's ex-fiancée reveals what broke up their 3-year relationship.

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"All My Children" star Chrishell Stause tells Star magazine that Matthew's close friendship with then-Broadway star Lea Michele is a major reason she called off their wedding. She had suspected that Matthew was cheating on her with Lea.

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"I decided to break off our engagement," she tells Star exclusively, "because I believed he was seeing other people and just wasn't ready to fully commit." Though both Lea and Matthew deny the rumors, Chrishell was not convinced and broke off the engagement in September 2007, just months before their wedding date.

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Matthew had proposed to Chrishell in 2006 after two-and-a-half years of dating.