The Kiss of the Spider Woman actor took a break from shooting Ridley Scott's new Robin Hood movie in southern England and travelled up to Scotland for the annual theatre and comedy event.
And the acclaimed thespian was so impressed with the actors in the Killing Alan production, he insisted on paying for all their alcoholic refreshments after the show.
The play's scriptwriter Phil King says, "It was brilliant. He waited for us afterwards and we went to the theatre bar. We tried to buy him a drink but he insisted on buying all of ours and then stayed out chatting until midnight.
"He was on his own. We've arranged to go see a show with him soon. It really is unbelievable.".