David is a psychologist and has been taking part in drug-fuelled gay orgies for the past 15 years.
"The sex is crazy -- utterly unbridled -- which of course is partly down to the drugs but also because you can act out all your fantasies," said the 54-year-old, who has been in a relationship for two years.
Chemsex -- taking drugs to enhance sexual pleasure and performance -- "has opened a whole world of possibilities to me", David added.
"Sex doesn't have to be limited to two people... There is a whole fantasy and transgressive side to it that turns me on. It is like you are in a porn film."
AFP talked to several French gay men who regularly indulge in the "party and play" (PnP) scene, mostly in the southwestern city of Bordeaux.
They described how their chemically-assisted group sex sessions sometimes last days, with sexual sensations and stamina boosted by psychoactive drugs they sniff, swallow and inject.
But the growing "high 'n' horny" subculture also comes with sizeable risks -- some of them deadly.
Most meet online with the "wired play" sessions involving multiple partners -- often at the same time -- taking place in people's homes.
Psychologist David said the atmosphere at sessions he has taken part in was "benevolent", with the hosts keeping an eye on what guests were taking and doing.
"You take your clothes off when you arrive and get straight into the action," he said.
Having sex with groups of up to a dozen men was a huge "opening up for me after my religious education, where the idea of being part of a couple was drilled into me by my family," said David.
But there are rules.
When you need a breather, "you might have a cigarette, an orange juice or a sweet... but there is never alcohol because that can be dangerous with some drugs," he warned.
Supermarket worker Hugo -- who asked that we change his name -- remembered how he felt like a "kid in Disneyland" at his first chemsex weekend.
"You are on a cloud, in another world, and you don't have to come down from it.
"You just marvel at it. You chat, you have sex with the best looking guys, you push the boundaries and there is no judgement -- no one criticises you," said the 42-year-old.
Every weekend for "two intense years" he plunged into "an extraordinary world".
"I was addicted to the atmosphere. It was all I thought about all week, waiting for Friday to come. It was like going to the casino, I needed my buzz."
But the adventure can quickly turn sour. In Bordeaux alone -- a small city of less than a quarter of a million people -- five people overdosed at chemsex sessions over an eight-week period this year. Three of them died.
Prosecutor Frederique Porterie told AFP that police were trying to work out whether the deaths were "an unhappy coincidence or whether a particularly toxic substance is doing the rounds."
Often bought on the net, the drugs are hard to trace, often coming in the post.
Methamphetamines like 3-MMC and 4-MEC increase arousal while inhibiting ejaculation and can keep users awake for days. Ketamine creates a feeling of euphoria and GBL or "blue nitro" -- an over-the-counter car cleaner -- turns into the relaxant and disinhibitor GHB once it enters the body.
"Use of these drugs is becoming more widespread," a police source told AFP. "They often come from the Netherlands and you can order them on the darknet."
Chemsex began in the United States and Britain around the turn of the century. While the phenomenon is "complex" and hard to gauge, psychiatrist and addiction expert professor Amine Benyamina said it could involve up to "a fifth of MSM (men who have sex with men)" in a 2022 report for the French government.
Nine out of 10 people taking part in chemsex are gay men, according to the French sexual health charity Aides. But experts say sexualised drug use also happens among heterosexual swingers and on the rave scene.
It's the morning after the night before at the Bordeaux male sauna and nightclub Le Crunch.
The jacuzzi, dance floor and private "backrooms" in the basement equipped with beds, lube dispensers and screens showing porn films are being cleaned. Several signs remind customers that drugs are not allowed.
But often it is "difficult at the door to spot someone who has been taking something", admitted co-owner Jess Royan, who has sometimes found "syringes in the cabins".
"These days a guy who doesn't take anything doesn't seem normal," said the shaven-headed 48-year-old, a part-time porn actor.
"With the mix of drugs, drink, the heat and the noise... once a month -- sometimes even once a week -- a guy collapses and we have to call an ambulance," he said.
David's partner Julien, 42, confessed to "playing with fire" himself in the past.
"For my generation, who have access to PrEP (Pre-Exposure Prophylaxis medicine taken to prevent getting HIV), there has been tendency to say, 'Why hold back, treat yourself and go bareback without a condom.'"
But then one day someone injected him without him knowing at a chemsex party. "I had a blackout," he said.
Something similar happened to former nightclub manager Alexandre, who passed out and lost his memory after a drunken evening when he accidentally mixed alcohol with a trace of GHB at the bottom of a glass.
"All it takes is a micro drop (of GHB) and you are out," said the 31-year-old, who asked AFP to change his name.
"I felt a numbness coming and I had the presence of mind to tell my friend that I wasn't right.
"I went into a room and slept straight for eight hours," he said.
Which is why people need to look out for each other during sessions, warned Hugo, the supermarket worker.
He described nights that turned predatory and "perverse" where guys "who would normally have difficulty getting anyone" preyed on others under the influence.
Beyond the overdose risk and of catching sexually transmitted diseases, chemsex has also been linked to depression, paranoia, anxiety and intense fatigue.
Addiction expert and psychiatrist Jean-Michel Delile said because people who tend to engage in chemsex are not typical drug users and are generally well-adjusted, they "underestimate the danger and the risk of getting hooked".
Some use the drugs to help them get over hang-ups about group sex and their own homosexuality. But for others the problems begin when it becomes more about the effects the drugs have on them than the sex.
"I know seven people in Bordeaux whose deaths were more or less directly linked to drugs and chemsex in the last five years -- either from overdoses or suicide," said Alexandre, who still occasionally takes part in sessions himself, though with a lot "less abandon".
"As soon as it ticks the little pleasure box, the brain wants more and is ready to sacrifice work and lie to your family to get it," he said.
The former nightclub manager also condemned the "omerta" about calling the emergency services when people fall ill, with other partygoers fearing they will be held responsible.
Which is why health NGOs say it is critical that PnP participants have support to turn to, and that digital monitors are out there online where they meet up to warn them of the dangers.
"The courts saved my life," admitted Hugo, who had to wear an electronic bracelet after being caught with drugs. "Only that could put a brake on me, given what I was taking to keep going three days non-stop."
David and Julien have also "calmed down" after getting support from a drug risk reduction charity.
"We were maybe a bit excessive," David acknowledged. "We have got back to more basic pleasures, enjoying life in other ways than just sex and drugs. Rather than splashing out 300 euros ($320) on drugs, we now treat ourselves with a trip to Barcelona."
