Some actors so completely occupy the roles they play that the lines between their on-screen and off-screen personas can get blurry. Sitting in a cozy hotel lounge with Rob Delaney and Sharon Horgan — the creators/writers/stars of the terrific sitcom Catastrophe, which premieres its second season on Amazon today — it's easy to feel like you're talking with Rob Norris and Sharon Morris, the protagonists of Catastrophe: warm, thoughtful, caustic, quick to laugh and to banter. Does it get annoying, I ask, that so many people conflate the real Rob and Sharon with the fictional Rob and Sharon?

"Yes. Yes. Yes. It does. Yes," says Delaney.

So let's clear up that misconception right away: Yes, Delaney and Horgan are playing "Rob and Sharon," and yes, the series draws liberally from their own experiences of marriage and parenthood, and yes, you can spot plenty of real-world parallels after a casual browse through their Wikipedia bios — but Catastrophe, for all its truths, is essentially a work of fiction.

Catastrophe began with a relatively high-concept premise: Rob, an American man on a business trip to London, had a week-long fling with Sharon, an Irish woman. Shortly after he returned home, she called and revealed she was pregnant. With no particular affection for his life in the United States, Rob moved to London, where he and Sharon resolved to take a shot at being an actual couple. The six-episode first season chronicled Rob and Sharon's halting steps toward building a life together: getting to know each other as actual human beings, meeting each other's friends and family, and growing alternately comfortable and uncomfortable with the possibility they might be in it for the long haul after all.

Catastrophe's title, Delaney explains, hails from a line of dialogue from 1964's Best Picture-nominated drama Zorba the Greek. "Zorba is asked, 'You got a family?'" Delaney explains. "And he says, 'I got a wife, I got kids. The full catastrophe.' That's such a great quote — and that's what it feels like when you have a spouse and kids. It does feel like a full catastrophe."

The key to Catastrophe is the whip-smart, ridiculously profane banter between Rob and Sharon, which sometimes turns their relationship into an arena for a crackling game over who can say the nastiest, wittiest thing. As writers, Horgan says she and Delaney are "allergic" to the tropes you might find in a more conventional family sitcom, like kids dropping catchphrases. And though Catastrophe is packed with laughs and conflict, the sources for both are extraordinarily unpredictable; a seemingly dramatic confession can dissolve into cathartic laughter, and a seemingly minor mistake can rip open a painful wound. "That's what happens in life, you know?" says Horgan. "Absurd things are said, and people deal with terrible things very, very badly. And sometimes with humor."

That dynamic, realistic approach to the conflict of a long-term relationship makes Catastrophe feel wiser, more truthful, and more resonant than a normal sitcom — and while Delaney and Horgan prefer not to be conflated with the characters they play, they're perfectly willing to draw inspiration from their personal lives. "I'm tired all the time because of how many children I have," says Delaney. "I'll be fighting with my wife, and then I'll just stop. Because I'm tired or I'm losing, so why not just stop? Rather than put a button in it and say, 'You know what, honey, you're right,' why not pretend something else is happening? Or go look out a window?"

Though Rob and Sharon's caustic banter rarely ends up sparking a genuine fight, Catastrophe's first season ended on a sour note. On their wedding night, the exhaustion and tensions that have amassed throughout the day explode, leading to a vicious shouting match that concludes with Sharon walking out — only to immediately return with the news that she's gone into labor.

It's a cliffhanger ending Delaney and Horgan had planned from the very beginning, but it proved polarizing with some viewers who, Horgan guesses, would have preferred a gentler parting note — like, say, Rob and Sharon smiling beatifically at each other over their newborn baby. That small element of discord, they say, is the only major difference they've noticed between Catastrophe's reception in the United Kingdom and the United States. "In the U.K., people were like, 'Oh, of course they had a knockdown, drag-out fight on their wedding night, after all that pressure they've been under!'" says Delaney. "Most people, in America, same thing — but there was that contingent of American Pollyannas who were like, 'How dare they? That's not supposed to happen!' And to those people, I'm like… Have you ever been in a relationship? Have you ever been under pressure? Spare me. They wanted it to end on a musical number. And that's ridiculous."

Catastrophe's second season skips past the immediate aftermath of that fight, offering a window into different phase of Rob and Sharon's relationship while broadening the scope of the series by digging deeper into the supporting cast: Rob's insufferable, eBay-addicted mother (Carrie Fisher), Sharon's ne'er-do-well brother (Jonathan Forbes), and a wealthy pair of friends (Ashley Jensen and Mark Bonnar), now in the midst of a trial separation. "We had a great time thinking of terrible things to happen to them," laughs Horgan. "Many catastrophes along the way."

Season two's final scene — which, in its own way, is just as fraught and unexpected as the scene that ended season one — was harder to come by. "We had an enormous original cliffhanger that we wrote [for season two], but it just didn't work," says Horgan. Delaney agrees, calling it a "writer's room misfire," though both decline to elaborate on the aborted ending in case they decide to use it someday.

So what about a third season? Delaney says it would be "legally irresponsible" to discuss the specifics — but he, Horgan, and the studio are all eager to make more Catastrophe as soon as the logistics have been hammered out.

Until then, viewers will be stuck contemplating the ending of an unfinished sentence. "Out of respect for the audience, why not end with a question mark instead of an exclamation point?" says Delaney. "Because then the audience gets to participate more. They're gonna have to think about it more. And then they have the disease of your show in their mind, and I want to poison people like that."