Rod Stewart. Crooner. Performer. Wearer of effortlessly messy hair. And now the singer can add ‘alcoholic philanthropist’ to his list of achievements after offering fans a free drink and footing a huge bill.

Stewart completed his fourth year in residency at the Colosseum in Caesars Palace yesterday in Las Vegas and, clearly in the mood to celebrate, decided to buy some of his fans a drink if they attended his gig.

He tweeted that anyone in Gordon Ramsey's Pub (located in Caesars Palace) on the night of the gig could get a free beer from him.

The catch: they had to wear a Celtic kit.

Stewart tweeted the generous offer, perhaps assuming there wouldn’t be many people in Las Vegas who would bave a Celtic top with him.

He was wrong.