"Everybody wants to know ... when do Cole and Helen have sex?" Treem says, tackling the elephant in the room before anyone else can. "I would say this: that I can promise you that's actually not going to happen this season. So, take that off the radar."

"They will always be intertwined in each other's lives in some way, and Cole and Helen do have some overlap this season for sure," Treem adds. "I think they have an interesting relationship because they have shared history but they don't really know each other at all."

Though the series was initially pitched to the Showtime network with a three-season arc, Treem says the story is plotted season by season. And that the original three-season arc has changed somewhat, in response to how each of the first two seasons has played out.

The show's multi-perspective nature also poses challenges. The biggest one, Treem says, is ensuring the writing is fair to both viewpoints as the affair between Noah (Dominic West) and Alison (Ruth Wilson) irrevocably changes their lives, and those of their spouses Helen (Maura Tierney) and Cole (Joshua Jackson).

"Part of the idea behind this show is that there is no such thing as objectivity because we all approach a situation through the prism of our own perspective," she says. "But then as a writer what you're trying to do is actually sort of prove otherwise in order to put yourself in the mind of one character."

The Affair then requires the writer to "put yourself in the mind of the other character and make sure you're being fair to both sides", she adds. "And I think you know we struggle to achieve that. And then we rely very heavily on our actors to say 'this feels false' for moments that perhaps work story-wise but are not necessarily deeply rooted in character."

The show represents, in some respects, a shift in how the narrative of "the other woman", historically characterised as a villainess, is told. Treem agrees there has been a significant change in the audience's perspective. Cases in point: The Affair's Alison Lockhart and Scandal's Olivia Pope.

"I don't know culturally why that's happening," she says. "On our show it was just because I had this idea that the archetype of a lover in an affair hasn't been explored in a complete, humane way yet. And I guess we were not the only people to have that idea at the exact same time. Sometimes you're the wife, sometimes you're the other woman, you're still the same person."

It also stems, she adds, from the notion that no one is wholly good or bad, that in the narrative of The Affair, no one is wholly without responsibility for the circumstances in which these characters have found themselves.

"We have this kind of idea on the show that everybody is part angel and part devil," Treem says. "You know, if you see us from one light we are a hero, if you look at us from another light we are a villain. There is no truth there. It's just about which way you are approaching the scenario."

While Treem gently stays away from topics which delve too deeply into the genuinely psychotherapeutic, she does acknowledge a belief that all relationships are, in some way, dysfunctional.

"All relationships are dysfunctional in some way, you know, and functional in others and I guess the question is if the relationship gets to be more pain than anything else then people get out of it, but I don't know," she says.

"I think we also have like a really high tolerance for pain as human beings and I think you don't like to be alone, really," she adds. "So it's scary to contemplate whether you will be happier on your own. There's something that's existentially terrifying about that."

Though she is reticent to divulge too much detail, Treem does confirm the third season of The Affair picks up the story three years after the second season and introduces a new character, Juliette Le Gall, played by French actress Irene Jacob. (Le Gall's character will be the window into a new "perspective".)

"I think this season is really about kind of accountability," Treem says. "It gets worse before it gets better with all of the characters having to take stock of who they actually are. And they are all very much at odds with themselves this season."

The rationale behind letting the story take a three-year leap into its own future, Treem says it seemed like a very organic place to start a third season.

"Partially it has to do with not wanting to repeat ourselves, so I try to start every season off with a bit of hypothesis at the beginning of the season," she says. "What do we want to explore this year? What are we interested in terms of these characters and their lives?

"We don't ever let the form dictate the content, we sort of do it in the other way," she adds. "And so we sort of can be a little loose about our storytelling and maybe because the show is always sort of structured as a fragmented story we feel permission to do that."

The season will also delve into Noah's relationship with his mother.

"It takes two parents to create a child and I do think that Noah's relationship with his father and his anger toward his father is kind of more obvious than his relationship with his mum," Treem says. "But I think Noah's relationship with his mum and what happened and the circumstances surrounding her death are very much a part of why he became the person he is. So we will find out."

WHAT The Affair

WHEN Showcase, Tuesday, 8.30pm