When Thomas Haden Church goes in, he goes all in. For instance, during his audition for the wine-tippling bromance Sideways (which earned him a Best Supporting Actor nomination in 2004), he stripped down in front of the director and casting team: “How can you deliver the vulnerability without living the moment?” he explains.

And now he’s all in for the HBO series Divorce (Sundays 10/9c, premiering this weekend), where he has to throw up on cue upon discovering his wife (Sarah Jessica Parker) is sleeping with someone else.

So we asked the 56-year-old, who lives on a 2,000-acre Texas ranch, a bunch of questions about the show and life. Here’s the best stuff.

“When it starts out, we’re in love, just the two of us and we’re going to do whatever we want. And then it’s like you’ve built an empire that you don’t want to rule.”

In Divorce’s first episode, your character Robert has to shit in a can, you burn your fingers in fondue, you almost get shot, and you throw up when you find out your wife is fucking around…
What a murderers row! Almost getting shot was my favorite moment. But throwing up is tough on camera, man, with the setups and angles. Ever seen Killer Joe, with Matthew McConaughey and directed by William Friedkin? Well, I had to throw up repeatedly. In Divorce, I had to keep loading up with this stew stuff to throw up. Of course it couldn’t be too warm because you’ve got to sit there with it in your mouth. I don’t know, did it work, was it funny?

You’ve been divorced yourself. How much are you like Robert?
There’s no real way to determine that anymore, because I’m just him. And not to give some ‘actor-y’ bullshit—‘Yeah, you’re him, sure you are!’—but for me, I just become him. As to why SJ and I work as well as we do together, and the chemistry we have, even when plotlines are unpleasant, there’s still a kinetic understanding between us. Everything physically, how I move, how I touch you, that’s him. And if I am to be authentic, I told Sarah, ‘You’re my partner, you tell me what happened, how I made you feel.’ And that’s how we are—we mesh very well.

There are dramatic circumstances in any divorce, but what’s the key to keeping your character funny yet real?
There are some absurd moments, but it’s not always overly funny. I was recently in an airport in San Antonio, and this woman is getting into it with her husband, and neither cared how many were listening, or if anyone was filming it, they were just going at each other. ‘I’m not angry at you, you keep saying I’m angry, but I’m not.’ This tragi-comic thing is happening right in front of me, and this couple has absolutely no sense of self-consciousness about their behavior in public. It’s ridiculous but it’s real life, and that’s what you draw on, reality. Even for the humor.

So what’s eating Robert and Frances, living behind a white picket fence in upstate New York?
Like in any relationship, this is who we were. At first, you’re having sex a lot, having romantic encounters, and being spontaneous. Then the first child comes, then the second, and all sorts of responsibilities start coming at you—pre-K, K, then grade school, social events with friends, the families want to be involved with the kids—and all these dynamics start to close in on a marriage.

And then one morning, you wake up and something has changed?
When it starts out, we’re in love, just the two of us and we’re going to do whatever we want. And then it’s like you’ve built an empire that you don’t want to rule, necessarily, anymore. And you want to go back to being footloose and free. Even though you love you children. But then you realize you just don’t love that person anymore. That you don’t see the same thing in her eyes that you used to see—you’ve lost that loving feeling, like the song goes. And maybe the reason you don’t see it in her eyes, is because she saw it in your eyes a year ago.

We all have family and friends who are divorced, so is it just part of modern-day reality, a natural part of marriage?
This divorce thing has been going on since I was a kid. Even in middle school, it didn’t seem like that big of a deal to me. After college, my friends started getting married, and then my friends started getting divorced. One of my closest friends, we write together, he’s been divorced twice. He’s a southern guy with a fundamental southern, Christian ideology. Yet he’s done it twice and it’s even more of a betrayal in his family. In the South, you’re supposed to fight as hard you as can and keep your wedding vows. But it is part of our fabric.

How does your chemistry with Sarah compare with what you had with Paul Giamatti in Sideways that worked so well?
From the first time Paul and I spoke on the phone, we talked for hours on end. We shared so many common interests—rock bands like Iron Maiden, books by Cormac McCarthy—and we laughed and talked. And then when got together to film, it really was like a brotherly romance, a bromance. Just a great experience and it continued on. It’s why we do what we do, to find that collaboration with your fellow actors.