The former Friends star was asked by the group to sign his autograph on their most intimate parts - but his blushes were spared when 20-year-old Efron walked by.
He explains, "The minute they saw Zac, all those lovely fleshy bits that were being waved in front of me vanished as they ran off screaming over to him.
"Good luck to Zac - I don't think I could handle all that adulation at my age."
Source: WENN