It was a sign I was getting too old for this sort of thing when, as I was having homemade toffee vodka poured down my throat (literally – there were no glasses involved), my main concern was getting splashes on my M&S jumper.
"Slushy!" yelled host Sam Thomas, holding the sticky bottle aloft like a still-beating heart as she scanned the room for her next victim. "Social!" boomed back the occupants of Chalet Robin, a luxury pad in Morzine (morzine-avoriaz.com) more used to putting up stylish thirtysomethings on a week's ski break than a rollicking end-of-season celebration. I rolled off the mezzanine stairs and crawled into the bathroom to dab my splattered jumper.
The Slushy Social is a week-long gathering which takes the mantra of "going out with a bang" and runs with it. It began in 2007 when Sam and Jon Dredge, owners of ski company More Mountain, found themselves with a spare week in Chalet Robin and invited all their mates out to celebrate the end of the winter in style. The snow was slushy, the banter social, the partying epic. A legend was born.
Five years on and the basement of their flagship property (as Robin has now become) is packed with 93 snowboards from nine brands, and enough bindings for a new pair every day of the month. The week, thanks to its alliance with Subvert (subvertboardstore.com), a Manchester-based snowboard store, has turned into an opportunity for participants to test all of next season's kit. Which explains why the basement is often jammed with all 33 Slushy snowboarders stroking boards with reverence, queuing up to get their bases waxed and murmuring about "rocker" and "camber".
Empty bottles of wine roll around the edges of the scene. The colours – of both boards and outfits – are intense; they scream happy, the riders pretty much wear glee. No mourning over saying farewell to the season here.
"Ha! They're the colourful people," laughs Robin chef Dan Jackson. "It's the end of the season and you're kind of bummed, but then these guys turn up and they are so amped that it rubs off on you."
There's a definite school's out vibe, probably because the clientele are keen snowboarders who moonlight as accountants, teachers, secretaries, business owners, welders. They are all away from work, in their element, and keen to make the most of it.
"The idea is that everyone mucks in," said Jon. "The chalet guys get to ride with guests; we slack off a little bit with the finer touches so we've more time to spend with people. The atmosphere is really relaxed."
Despite Slushy being spread over three More Mountain chalets, everyone descends on Changabangs, a burger joint by the Prodains lift in Avoriaz, for lunch. It is testament to the mischievous as opposed to antisocial nature of their revelry that they are well known to – and happily welcomed by – the owner.
Sam and Jon and their Subvert counterparts, Darren Ford and Lorraine Smith, organise basketball tournaments, après-ski and chalet gatherings to keep the carnival atmosphere going off the slopes. They put the emphasis on participation without forcing the party.
"It may look ad hoc, but a lot of effort goes into this week," says Darren. "We love the social scene, riding with people who become friends over the course of the week, and we get to see another side of people who we usually only see in the shop."
First dibs for Slushy tickets go to people who have shopped at Subvert or previously stayed with More Mountain. After that it opens up to everyone else – including, whisper it, skiers.
"You can snowboard as well though, right?" says welder Pete, eyeing my twin tips suspiciously.
Indeed I can, and after spending one day fending off jokes about my planks I spend the next five trying to hang on to a K2 Eco Pop board. Let's face it, it's April: if you want late-season powder you need to head to Scandinavia, not the Portes du Soleil. But the point of the Slushy is to make a party out of what you do have, and with that many people in your group it's easy to take over entire pistes. Which, it must be noted, tends to egg people on to attempt rather foolhardy things, such as cliff drops to flat, and skidding across lakes while others point, cheer and laugh from passing chairlifts.
There is a saying in Morzine: "The Mutzig made me do it." And it's believable. Mutzig is a devilishly strong beer sold in Bar Robinson, on the main strip. It's a bar with little finesse, limited choice and zero interior decoration, but the Mutzig draws in the punters like bees round a honey pot. By 4.30pm each day the Slushies are there, splurged across the terrace, their clashing hues fighting with the spring sun for retina-burning dominance.
Plans for the evenings are fluid, dependent on such variables as the amount of revelling that accompanied dinner and how many people survived the lake-skidding faceplants. Once the Slushies pick an evening venue, though, they tend to fill it up.
"Look at these people," yelled the barman at the Cavern club, over his heaving bar, Slushy logos flashing around the room. "They're so happy!"
And if a good thing is going to come to an end, you may as well go out with a smile – if not smears of toffee vodka – on your face.
• Seven nights' full-board at Slushy Social (8-15 April) with More Mountain (+33 686 021805, moremountain.com), including lift pass and airport transfers, but not flights, costs £499pp. EasyJet (easyjet.com) flies from various UK cities to Geneva from around £145 return
