FXX's You're the Worst may have one of the most truly terrible — and relatable couples — on TV.

Created by Stephen Falk (Orange Is the New Black), the comedy — which centers on two horrible people, Jimmy (Chris Geere) and Gretchen (Aya Cash), and their misadventures in life, love and romance — quickly became a critical darling during its 10-episode run on FX. The anti-romantic comedy will move to younger-skewing cable network FXX for its sophomore season, which will focus on a "big issue" and feature the return of fan-favorite episode "Sunday Funday," with a whole new twist.

The Hollywood Reporter caught up with showrunner Falk ahead of the show's Friday panel at the ATX Festival (moderated by this reporter) to get the scoop on why viewers root for Jimmy and Gretchen and what to expect from season two.

Looking back on season one, how did Gretchen and Jimmy get to be this damaged? Is this a case of nature vs. nurture?

I think it's a combination of both. Gretchen, we met her parents and they seem like pretty uptight, country club types, and she probably rebelled against that pretty early. There was a sense in her that she had to be the good kid, and so she learned to live a double life and not let anyone know her true nature and kind of lie about everything, as we established. She kept up this good persona while being tempted by the worst parts of her nature and probably also her background. It's probably nurture, partially, but not in the way that one might expect in a way of acting against more repressive elements of her family. We will find out more about Jimmy's background in season two. He rebelled in the opposite way: His family is English white trash in a way, and he immediately wanted to distance himself from his tiny little industrial, lead-mining town and take on this posh accent and immediately go to London and L.A. as soon as he could and get far away from his roots and reinvent himself. But as we'll sort of learn, the past always comes back to haunt you.

We have to talk about the "Sunday Funday" episode. Where did the idea for that episode come from?

We struggled with that a lot. I wanted to early on do an episode that broke form. With the pilot and episodes two through four — which constituted Act 1 of the 10 episodes — I wanted to start Act 2 off with something visceral and fun. We played with a lot of ideas. We had heard this term of "Sunday Funday" and thought it was kind of stupid and something Jimmy would hate and it built from there. When I was writing it, I was worried: "Is this the show?" I wrote on the outline, "Stop fighting this and embrace this as a fun and silly episode." I knew we had to continue [Jimmy and Gretchen's] relationship back and forth and them trying to figure out rules of their relationship. We wanted to make sure there was an arc for each character and a reason they were doing this — an internal struggle they had to come to. Then we stumbled on using the Peter Gabriel vs. Phil Collins argument as a metaphor for Jimmy trying to get Gretchen to not go to New York with Ty.

Will Sunday Funday be an annual tradition?

Yes, we're going to do another Sunday Funday episode. But it's not just the same; like with all sequels, you have to up the stakes. It will be a seasonal version.

It seems only fitting that it be Jimmy's turn since everyone else has had their day. Will it still be around the middle of the season? How do some of this year's destinations compare with last year's?

Without giving anything away, I think that's a good idea and notion (laughs). It will run somewhere around the middle of the season. It's a really bonkers element of every department; we're working on it right now and it's quite a challenge. If we pull it off, it's going to be spectacular. There's a point to the destinations more than just to have fun; it's very themed. Again, they're doing it for a specific reason, or at least one or two of the characters are and maybe the others don't know why they're doing it. It's more themed than specifically East Side L.A.

What is it about Jimmy and Gretchen that makes you want to root for two terrible people?

They stand in for a wish fulfillment that we all have for our relationships, and that touches on fear that we all have when you're sharing your life with someone: that you're going to be judged. Jimmy and Gretchen are never afraid to tease each other but when it comes down to it, the dark parts of themselves are embraced by the other. They know right from the get-go — right when they meet at this wedding after having ruined it in their own ways — that they are not the greatest people and they've found a kinship. In the pilot, when Gretchen tells Jimmy that she burned down her high school to get out of a math test and he laughs and says, "genius," and moves on, that was something she suffered as a kid being constantly judged and hiding her bad side, and this is someone from which she doesn't have to. The show serves as an idea that even the dark parts of ourselves — and hopefully we're not as dark as they are — but the damaged parts are still deserving of love. … There's also a great sense of play between the two of them and that they genuinely like each other. We look at and wish we had that. And the fact that they get to do and say and behave in ways that we're afraid to, it's why people are attracted to villains: There's a wish-fulfillment element of that of people behaving in ways that we never would but perhaps we would like to.

Now that Jimmy and Gretchen are moving in together — though not totally their choice and a bit premature — where does season two go?

Because we're entering territory where we have two characters moving in together and that's obviously a built-in story for a romantic comedy, my mandate was to make sure another romantic comedy TV show — and I wrote names of some of them on our writers room board — was to make sure blank show wouldn’t do this. We have the built-in story mechanism but we want to make sure we're always tackling it in a very specific Jimmy-and-Gretchen way. In season two, we're following through on that and not backing off them moving in together for wrong reasons or a bit early. We're tackling that in weird ways and telling stories that only could really be told with these characters. They're going through growing pains but they're going about them in ways that I think will be very in line with who these characters are.

This season gets weirder and darker. We are going to be tackling a big issue — and it's not an issue that's necessarily funny; it's kind of the opposite (laughs). We're tackling that from the beginning of the second act, which I consider episode five all the way through. It's something when I pitched the season to [FX boss] John Landgraf and team, they were understandably a little cautions but never tried to get me to back off it. They gently reminded me to make sure it was still fun, and I think we've found a way to do it.

Can you say what the issue is?

I can't yet. It's something very widespread and something a lot of people I know are dealing with and something a lot of people in general deal with. We're trying something a little more difficult.

Jimmy and Edgar's (Desmin Borges) friendship is so great. How will having Gretchen there change things?

The deal was that Edgar does Jimmy's bidding and manual stuff that he considers beneath him or is incapable of doing. With a second person, that becomes an issue but at the same time Edgar genuinely likes them together and thinks she's good for him and has stated as much since the pilot. While there will be tension, I don’t think there's a lot of fun to be had with trying to get too much mileage off our main characters disliking each other or having real problems with each other's existence. With Edgar, we thought it was fitting — and it comes out of Gretchen moving in — that he then takes this opportunity to try to forge his own life and have some independence. So we'll get him finding a hobby and perhaps a little love.

Could Lindsay (Kether Donohue) be part of that love for Edgar? There were definitely some sparks for them in the season finale, including the scene where he smells her hair.

(Laughs.) We try to always follow through on everything that we set up. So yes, that will be a part of it but perhaps not the whole story for Edgar.

Gretchen and Lindsay's relationship is interesting as they're both trying to grow up. Where does their relationship go now that Lindsay's husband wants a divorce and Gretchen and Jimmy are moving forward?

Lindsay has been left by her husband and is alone and whether that is good for her or not shall be seen. She's having her life rocked. For me, our main characters' love for each other and friendship and fun hanging out together is paramount. That will continue. It's a pretty nice relationship they have and it's particularly fun for us to portray a female relationship that isn't judgmental or competitive. While they tease each other — perhaps with Gretchen teasing Lindsay a bit more since she's an easier target — they truly support and love each other. Like we did last season with Edgar and Lindsay, we're going a little meta realizing that they're sidekicks and what that means and rejecting that. We're going to have fun in an episode with Gretchen and Lindsay realizing they talk about the dudes in their life a lot and trying to figure out how not to.

How big of a role will Paul (Allan McLeod) have in season two now that he's said he wants a divorce? Could we meet his new love interest?

Yes and yes! He's definitely a big part of season two and we will meet Amy, the girl he meets on a home brew chat room. We have a lot of fun new characters this season, with three major recurring characters [including Collette Wolfe as Edgar's new friend].

Who do you really think is the worst, Jimmy, Gretchen or Lindsay? Because Edgar is pretty great and on another level.

I would pick [Lindsay's sister and brother-in-law] Becca (Janet Varney) and Vernon (Todd Robert Anderson). It was important to have really shitty people, although the problem is I love all the characters. I don't think Edgar qualifies — he's too good a soul. But probably Jimmy, just because he's so arrogant and it's for no reason, which I find hysterical. That's a very obnoxious quality if you had to know him in real life, but to get to write him and see Chris playing him is an absolute joy so it's hard for me to say he's the worst. But Lindsay is pretty horrible, too: She cheats on her husband a lot and isn't the sharpest tool in the drawer and doesn't care. And Gretchen is an absolute mess; we saw her apartment, we saw her drunk driving and hit a cop. They're all probably neck and neck!

You're the Worst returns later this year on FXX. What are you looking forward to seeing? Sound off in the comments below.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit