‘I think we’re nearly here,’ says our taxi driver, with some trepidation, as we approach Folsom Street Fair, the world’s most famous sex street party. The clue is someone wearing nothing but a huge bunny head and a tiny little G-string making their way along the road.   First stop, after giving a donation at the entrance barrier – the festival itself is free – is a huge hangar-sized bar for some Dutch courage, where a young man, who turns out to be from Swindon, tells me I’m going to be way too hot in the San Francisco sun in my boiler suit. I ask what brings a straight English man to America’s most notorious and queerest event. He’s impressed by my ‘gaydar’ but I point out that he’s wearing board shorts and practically every other man – apart from me – is in a jock strap. Except for the guy on the street outside the bar who is sitting naked apart from a Stetson on his lap to hide his modesty. It’s not clear why he’s taking the trouble as no one else is bothering. Even the high-powered lawyer friend who has brought us isn’t hiding very much.   Folsom Street Fair, which is celebrating its forty-first year in 2025, is an eye-opener and no mistake. Taking over several closed-off blocks in the South of Market district, California’s third biggest outdoor one-day event is here to celebrate sexuality and sex – and yes, kinkiness - in all its forms. Starting out as an LGBTQ+ event to wind up Leather Pride Week, it now attracts anyone with a taste for wearing next to nothing, getting their fetish on and having intimate moments while everyone looks on or even takes photos. Like the middle-aged woman in a basque who has brought her naked husband down to show him off. Well, there’s quite a lot to show and he doesn’t seem to mind.   On a stage is a next-to-naked Twister competition, while across the street a full-size wrestling ring compered by drag queens features bouts by strangely mis-matched contestants here to showcase revealing outfits rather than actually win. Or you can always just get spanked to raise money for charity.   A fully kitted-out cop complete with shades and nightstick passes by, the only clue that he’s not real being the fact that his outfit is all rubber. He sees me eying him up and asks if I want a feel. Another clue. And then there’s the plus-size woman on huge platform boots whose outfit only comes up to her waist and then continues when it gets to her neck. And there are, of course, lots of ‘pups’ running around but then you see them at most LGBTQ+ events: men whose thing is wearing a foam rubber doggy head, usually teamed with not much more than a jockstrap, who behave, and wish to be treated, as if they were real dogs. Don’t offer to buy them a drink, put a bowl down.   But nudity is the real name of the game at the Folsom Street Fair with the most modest wearing a G-string or jockstrap or cowboy chaps covering the legs with nothing where jeans would usually be… but this is San Francisco and full nudity is legal any day of any week anyway. Have lunch on Castro Street in the gay neighbourhood and you’re sure to see an elderly gay man in nothing but boots and a knapsack walk past, while outside the Starbucks on a sunny Sunday afternoon, a male/female couple are chatting over grande lattes in nothing but footwear. Apparently, the rule is if you want to go naked, you have to leave your house naked… but how would they police that? Oh and you are not allowed to have contact between public furniture and your body while naked. Which seems more than fair.   But all that is just day-to-day. Folsom Street is a much-copied special occasion (there are versions in Berlin and Toronto) that takes over the whole weekend in the bars and clubs of San Francisco and, when the actual Sunday afternoon event winds down, relatively early around 6pm, all the action heads back to those bars and clubs.   Oh and the guy in the hangar bar was right, by the way: the boiler suit was too hot in that unseasonably balmy late September weather… but I didn’t take a stitch off. Spoilsport? Maybe.   Virgin Atlantic flies daily between London Heathrow and San Francisco, with fares from £440 return, virginatlantic.com.