London's a brilliant place to be around Christmas, but what's it like for the people who make the magic happen? Jonny Ensall hangs out with the elves to get the skinny on the fat man at Westfield Stratford City.
Excuse me a moment while I become my grandad, but I'm not sure about these newfangled Santa's grottos. In my day, you would visit Old Red in a shed in your school's car park, inside which the man who also coached the under-tens football team would hand you a shoddily wrapped plastic sword with a 'ho, ho, ho' and a stroke of his felt beard.
But this, I'm forced to admit, is 2015. When grottos are made by Dreamworks and boast iPad games, virtual-reality sleigh rides and production values that would make Secret Cinema want to pack it all in and just watch 'Elf' under a duvet.
Outside Westfield Stratford City you'll find such a grotto. A big one. More of a mansion, in fact. At peak times the elves running the 'Shrek'-themed adventure will host a family every four minutes for up to 12 hours a day. By the end of the grotto's run, over 20,000 London children will have met Santa.
But - and this is a massive spoiler - it's not the real Santa. I know this because I'm 30 years old. And also because there are three of them. 'The public are never aware of the huge scam,' says grotto manager Fraser. Two Father Christmases dole out presents in identical rooms, side by side, while a third takes his break. Then they rotate.
'There's a code for swapping a Santa,' says Fraser. 'We call it a "Christmas pudding". It's a military operation to make sure no one ever sees two Santas crossing streams.'
It's hard work, lying to children. And - just like with a sordid hotel room affair - real names have no place in the grotto. Elves aren't called Kev or Jules, after all, so instead I'm introduced to Cranberry, Cinnamon, Snowball, Moonbeam, Precious, Stardust and Sparkly.
'Sometimes I shorten it to Sparkle,' says Sparkly, who seems surprisingly upbeat about the whole Christmas thing. Surely the endlessly looping carols would be enough to make you turn to drink and drugs? 'Not yet! But come back on Christmas Eve...'
There is a fair bit of white powder ('snow') lining my route to meet Santa, but the big guy seems merely merry, not high as a sleigh. 'As long as there's enough mulled wine being brought in,' he chuckles. How old is Santa, I ask. 'Old enough to have bounced your grandmother on my knee!' Is he getting a Christmas bonus this year? 'The best one! The light of love in a child's eyes.'
This guy's good, and I can see that for your average seven-year-old, getting to meet him is a BIG DEAL. Like getting to meet Beyoncé. He's also cuddly and properly attired. Unlike the scruffbags of yesteryear, this Father Christmas is as real as... the real Father Christmas!
What is that warm feeling creeping into my bones? Could it be mirth? I can't believe it - Santa has successfully de-Scrooged me. Bah, humbug!
Want more festive fun? Take a look at our ultimate guide to Christmas in London.