STEPHEN Adly Guirgis was in a bar when one of the seeds for his play started to take hold. The New York born playwright, director, actor and screen-writer was out with a group of male friends, and they got talking, as men do, about women who weren’t their wives or partners, but who they’d been intimate with, or as intimate as you can get without touching.

“I was noticing people being unfaithful in their relationships pretty often,” Guirgis says about the roots of his 2011 Broadway hit The Motherf***** with the Hat, on the eve of its revival at the Tron Theatre in co-production with the Cardiff-based Sherman Theatre.

“One guy said that he had all these things going on with other women, but that it was OK, because they didn’t have sex or touch, they just got naked. And everyone was going, yeah, yeah, not touching, like it was fine. I said, wait a minute, if your girlfriend went home with a guy, took her clothes off, and didn’t have sex, but they both masturbated, would you be happy with that?”

Guirgis doesn’t say what the answer was, but the response ended up in the mix of his story about Jackie and Veronica, a long-term couple whose relationship is compromised when Jackie gets out of prison and discovers another man’s hat in their apartment. The fact that he’s cleaned up and Veronica hasn’t doesn’t help, as a series of misunderstandings threaten to spiral out of control.

“When you’re young, your friends really matter,” says Guirgis. “They’re like your tribe, then when you get older things become more complicated, and the rules we’re taught as children don’t necessarily carry forth into adulthood. You might have a friend who is totally loyal to you, but is a scumbag to women. We don’t necessarily all fit into a tidy package, and the play is a story about finding a morality or a manner of being that works for you.

“If you can go out drinking every night and can handle it, fine, enjoy it. If you can be unfaithful with other women and can handle it, great. But if you can’t handle it, you’re going to create nothing but misery for yourself.”

Guirgis, who was born to an Egyptian father and an Irish-American mother, started out as an actor.

“My mother wanted to be in the arts,” says Guirgis, “but it was the depression and she never had the opportunity. It was different for me and my sister. We didn’t have much money, and my mother was very strict about how much TV we could watch, but she would take us to movies. Not just new movies, but old ones too. She wanted us to be cultured, and I fell in love with it.”

Guirgis landed up with LABrynth Theatre Company, an off-Broadway set-up started by actors in 1992 as a way of flexing their creative muscles. Guirgis found himself writing short plays, and was encouraged to do more.

“I kind of fell into it,” he says. “I didn’t study it. It was a conflict for me, because I wanted to act, but because I became aware that for whatever reason I’d been given this talent to write, and I had a responsibility to it. I thought one day it will suck and then stop, and I’m sure that’s coming soon, but in the meantime I better use it while I can.”

One of Guirgis’ early works, Jesus Hopped the ‘A’ Train, was seen at the Edinburgh Festival Fringe in the early noughties. It became a hot ticket, and transferred to the West End.

“Oh, boy,” says Guirgis. “That was our coming of age as a theatre company. Things really took off for us after that. It was a really special time.”

By that time Guirgis had already struck up a friendship with Philip Seymour Hoffman, the mercurial acting talent and left-field Hollywood star who died of an overdose in 2014. The pair became close collaborators, with Hoffman directing five plays by Guirgis.

“We discovered we had simpatico,” says Guirgis. “With Phil I felt liberated. In the early days I purely wrote comedy, but he gave me license to do anything I wanted. He could understand what I did intellectually and emotionally, and could communicate that to actors.”

If Guirgis had of had his way, Hoffman would have either directed the original production of The Motherf***** with the Hat or else played the lead. Both offers were declined, with comedian turned Hollywood player Chris Rock taking it on instead.

“Motherf***** was the first play of mine Phil didn’t direct,” says Guirgis. “He said he loved me, but he wanted to spend time with me doing friend stuff. We got so consumed by the work, and we’d go into these things with big casts and with me still writing it, but this one was different. It was finished. I said, Phil, here’s a play that’s already written, and which only has five characters, why not direct it, and then we can go fishing.”

Hoffman died a couple of years later, having never directed another play by Guirgis.

“If Phil had died and I’d had no experience of working with another director, I don’t know where I’d be,” Guirgis admits. “Being forced into it confirmed to me that I could do that. Working with Phil, I’d be like, is this play successful because of the writing, or because Phil is a genius? And he was a genius.

“But as great an artist as Phil was, he was an even better person, and an even better friend. He was the last person you could imagine would fall. He spent his life helping people. But addiction, or whatever you want to call it, is a bitch. I can guarantee he would never, ever want to leave his kids the way he did, but that’s what happened.

“Again,” says Guirgis, bringing things back to The Motherf***** with the Hat, “it’s down to what you can handle, but addiction is ruthless.”

With TV writing credits on the likes of NYPD Blue, Guirgis spent three years working with the equally driven Baz Lurhmann on The Get Down, a $120 million-dollar series charting the rise of hip hop and disco in the Bronx as seen through a group of teenagers.

“I grew up in New York during the birth of hip hop,” says Guirgis, “and a lot of the show I’m very proud of, but I’m more at home in the theatre. Sitting in those offices in LA, they kept on bringing me different chairs. Ordering lunch took 40 minutes.”

Guirgis is currently at work on a stage adaptation of Sidney Lumet’s 1975 bank heist thriller, Dog Day Afternoon. He’s also writing a sequel of sorts to The Motherf***** with the Hat for Netflix.

“The world has changed since I wrote the play,” he says. “You can see characters with addictions in a million things now, so rather than just tell the story, I’m planning to take one of the strands of it and pick things up six or seven years later.”

As for the play itself, “I think it holds up fairly well, but whenever I’m writing extreme characters in extreme situations, if I’ve done my job properly, my hope is that the audience are not just watching a play about the people onstage. My hope is that they can see themselves in some way, that they can see themselves and the people closest to them.”

The Motherf***** with the Hat, Tron Theatre, Glasgow, March 1-17