"Panto," for the non-Brits and Americans not so anxious to show off their anglophilia that they would rather go and look it up on the internet than ask, is short for "pantomime." It's traditional for British families to take their children to a panto for Christmas. It's considered a children's activity, I believe, because adults don't want to admit how much they enjoy this form of theatre.
Audience participation is a key element of the panto. You boo and hiss when the villain shows up, and cheer for the hero, and shout warnings to him when terrible things are about to happen. You're allowed to groan loudly at the jokes when they are very bad. It's also typical for at least some of the cast members to be cast in roles of the opposite gender.
We saw "Aladdin" at the Old Vic. Ian McKellen played the part of Widow Twankey, Aladdin's mother, and he completely stole the show. Not just because of his fabulous outfits, either, although the image of him clad entirely in white spandex with gold-trimmed bell-bottoms and a blonde wig a la Abba will never leave me. He had many of the best – and dirtiest – lines. He pranced onto stage in a miniskirt and a giant feather-topped hat, carrying a shield with the British flag painted on to it, turned his back to the audience, waggled his bum and said coyly, "Please note, this is Twankey's grand entrance."
We had to endure a lot of pretty cheesy gags ("Is that my corset?" "Course it is!") and a song or two by Elton John, but fortunately there was enough political and adult humor to alleviate the occasional tooth-grinding sweetness. For instance, the Emperor's first illusion was conducted with a magic Blunkett, which he claimed would fast-track the coppers (Hanky and Panky) directly to Aladdin's location. While Widow Twankey and her faithful helper Dim Sum were hanging out the laundry, they pored over, respectively, Ann Widdecombe's thong (she's a legendarily ugly MP), a gigantic bra belonging to Jordan ("It's shrunk in the wash!") and a pair of Bush's underpants ("Why's it got a flag on the back?" "So Tony Blair can hear him when he speaks.").
A pair of schoolboys sat next to me. One of them had clearly seen the panto before, because he spent a lot of time explaining the less obvious jokes to the other in a loud whisper. They were baffled when the adults laughed at the Widow Twankey suggestively telling the Emperor that she had something cheesy bubbling in the oven for him.
I'm sure they'll figure it out eventually.
Tomorrow night we're going to this. We are dressing up. There will be pictures, oh yes.