It offers heightened experiences but comes with horrifying dangers (Warning: Graphic content).

Until recently, "chemsex" was something that existed largely in the gay or bisexual communities. But now "PnP" or "Party and Play" has crossed over into the straight world and the term “chemsex” has moved into the urban lexicon. It's a catch-all for people having sex while high on drugs, such as crystal meth, GHB , ecstasy, ketamine and cocaine.

Purveyor of hook-up pop The Weeknd, even wrote an ode to it, with his mega hit "Often". "You on your phone texting your friend to come f*#k. I wonder if it's the druggies wit hoes or the million of bucks," he asks, almost rhetorically. While singer and rapper Angel Haze puts out there, rapping, "Can we just get high? Then find each other through each others' thighs".

"I was totally uninhibited"

While Sydneysider Ally* 30, never went to a chemsex party per se, but she has had a lot of chemsex.

"By day, I worked in HR. By night, I was 25 and partying. While I'd always felt a little shy having sex, however, on cocaine and MDMA, I was totally uninhibited. Then I met a DJ, who gave me my first bump (a small mound) of crystal. As soon as I snorted it, it made me feel instantly horny like no other drug – it was such a heightened sexual experience. We would have sex for 12 hours straight. Literally. We’d only stop to go to the bathroom or have a sip of water.”

According to Ally, the sex became compulsive and more extreme, while the weekends started earlier and finished later. And the lovers she took became more random.

"When you have chemsex it's like you're pushing to annihilate sexual boundaries and each other –fisting, hardcore anal, watersports, threesomes, you name it, I did it. On drugs, I felt like a wild, bad girl. Then came the comedown and the shame - terrible Tuesdays, followed by weepy Wednesdays.

"Then I'd be ready to party again on Thursday. I didn't recognise myself as a pockmark faced addict portrayed on the anti-ice ads. They were on ice; I was on crystal – despite the fact it was the same drug. It ruled them; I used it for sex and recreation. That was my delusion. It was a cycle I was in for about nearly two years until I had to admit I had a problem and sought counselling with a therapist."

'Men using drugs to lure women into sex'

Ally is not alone. How's this for a sobering statistic — an Australian survey of young adults found 92% of people who had had casual sex in the past six months had used alcohol or drugs. "The scary thing is cocaine is being treated as if the user is drinking a glass of wine," says Sexologist Nikki Goldstein. “A lot of men are using it to lure women into sex. "You want to do a few lines together" has become a new pickup line."

But what also worries Goldstein about sex in an altered state is often high-risk unsafe sex. "People are putting their health at risk. A lot of people don't use condoms when they're drunk or high. If you have a sexual encounter, it's consensual, and you're there because you want to be then that's fine. But the question you have to ask yourself is if you weren't under the influence, would you be putting yourself in that position?"

The dangerous cycle

However, there is nothing new about having sex in an altered state. "It goes back to the ancient times," says counsellor and therapist Chris Mordue, who has worked in drugs and alcohol treatment centres for ten years and is now in private practice.

"People first use drugs to feel good and connect. It lowers inhibitions and heightens confidence. The danger is the drugs can become the sexual driver and have a detrimental affect on your life. The cycle goes, craving drugs when you have sex and sex when you take drugs. While most recreational drugs user don't become addicts, there is still high risk associated in taking Class A drugs."

For Ally, chemsex produced sexual burnout. "Weirdly, it's depressing to think that I'll never have wild sex like that again. It's taken me three years to readjust to 'vanilla sex.' I still haven’t found a boyfriend, so I can’t quite imagine how connected sex will feel. I hope it will change my mindset. Sometimes I still crave hardcore drugged out sex, but I know it's too dangerous to ever go back."