Kristen Bell was mortified when she first brought fiance Dax Shepard home to meet the family after her aunt made an awkward joke about her love of masturbation.
 
Bell introduced Shepard to her relatives last November for Thanksgiving, and the actor eventually proposed in January.
 
But the star was left speechless at a formal family dinner, when her "sweet" aunt tried to lighten the mood with a filthy joke.
 
She recalls, "At Thanksgiving, which is about 15 people - 10 of which were over 75 - my sweet, sweet aunt... decided she was all of a sudden bit by a commy (comedienne) bug. And she says, 'I've got a joke!' And we all thought, 'OK, this is weird.'"
 
And Bell was stunned when she heard what came next: "She looked at us and she said, 'What has two thumbs and loves to masturbate? This girl!' My cousins and I did not know what to do... You gotta know your audience - it was not appropriate."

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