Zac Efron in His Underwear on the Set of Dirty Grandpa

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Zac Efron in His Underwear on the Set of Dirty Grandpa

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Zac Efron flashes toned torso as he films Dirty Grandpa

Zac Efron flashes toned torso as he films Dirty Grandpa

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Zac Efron in His Underwear on the Set of Dirty Grandpa