Actor J Smith-Cameron was born Jean Isabel Smith in Kentucky in 1957. A Broadway veteran, she is also known for her supporting roles in TV dramas such as True Blood and Rectify. She’s currently playing Gerri Kellman, general counsel to Waystar Royco, on HBO/Sky Atlantic hit Succession. Smith-Cameron is married to writer-director Kenneth Lonergan and they have a 17-year-old daughter.

How are you feeling about Succession’s Emmy win for outstanding writing last weekend?

I was delighted and still am, because it’s so brilliantly written: bold, clever and thrilling to work on. I couldn’t admire [creator and showrunner] Jesse Armstrong more.

Your character, Gerri, is proving to be the cult star of season two...

I don’t know about that but, if so, it’s delightful. I think it’s because she’s always having those eye-roll moments, looking down her glasses or taking a pointed sip of water, which the audience find satisfying. She’s in the inner circle but slightly removed because she’s not a member of the Roy family. Gerri’s largely unflappable so it’s fun to watch when she does react. And those reaction shots are pretty meme-friendly, as it turns out.

Are you getting recognised more as the show has taken off?

Definitely. And Succession seems to have very diverse fans, which is great. I don’t dress or wear my hair like Gerri, so sometimes at the end of a meal at a restaurant, the waitress will suddenly go: “Wait a minute, aren’t you…?” It’s often a slow dawning.

Why do you think season two is so much bigger than season one?

Partly because the show very confidently took its time to set itself up. There are lots of layers to it and the style has this sort of cold objectivity. Jesse and the other writers relish the characters’ foibles but don’t glorify them. They show how awful they are but don’t spell things out or over-explain. It’s deftly done and finding that exact delicate tone took time. The audience had to hang in there but when they did crack the puzzle, it was extra-rewarding.

J Smith-Cameron and Kieran Culkin in season two of Succession. Photograph: HBO

Gerri’s relationship with Roman Roy, played by Kieran Culkin, has developed into something sexual. Did you see that coming?

It took me by surprise as much as viewers! In season one, when we were shooting scenes in the UK, Kieran and I did a little improv that wasn’t used. They often let us do an extra, looser take or leave the camera rolling at the end of a scene. It was just jokey repartee about mixing martinis because we both, on occasion, order one then we pretended to check each other out as we walked away. I’m not sure it was flirtatious but there was some little frisson between us. Everyone found it funny and that might have informed the subsequent storyline.

You and Kieran knew each other already. Did that make the intimate scenes easier?

I’ve known Kieran for years. He’s been in several of my husband’s projects and we have lots of mutual friends. It was a great luxury to have that rapport already. We knew each other’s sense of humour.

What is it that makes their relationship so fascinating?

It’s unexpected and perverse. I guess the shock is part of the fun of it. But there’s also this burgeoning mentor relationship which is very tender. I’d venture to say that’s what interests Gerri more – to be able to influence one of the Roys and form an alliance.

And you got to coin the term “slime puppy” …

Ha, yes. I think that was my improvisation. I looked back at the script and that certainly wasn’t on the page. We were talking on the phone and as Roman was, shall we say, finishing, we’d run out of dialogue, so I said a few different things. That one made it into the cut. It was their first time and Gerri was sort of disgusted but the more disgusted she sounded, the hotter it was for him.

What did you make of your character when you first saw the part?

It was originally a male role, Gerry with a Y. When I first auditioned, they’d just decided to call women in to read for it, too. I stumbled across this idea that Gerri was someone who’d wince and give withering glances. I also figured she’d been with the business a long time, so had to be a survivor. Someone who could step around booby traps and perform under pressure.

Well, Roman said she’s “a stone-cold, killer bitch”.

He’s such a flirt! He says that admiringly because Gerri is quite a badass. She’s a high-stakes player but also relatable because she’s unnerved at times. Sometimes she’s just trying to stay on the surfboard. That makes her interesting.

This week’s episode is filmed in Scotland again. How was that?

We had a blast. We got to shoot in the new V&A in Dundee, which is very cool-looking.

In your mind, are the Roy family a take on the Trumps, the Murdochs or someone else?

An amalgamation. I think the writers artfully pick and choose qualities they’ve observed from all these families and their power structures. It’s partly about what life is like if you’re super-rich with that much power. But to be a junior family member under someone like that is weirdly powerless – they have the trappings of this great life yet they’re frustrated by their impotence.

In Succession, women often seem the smartest ones in the room. Might they eventually take over from the men?

That would be interesting. It’s certainly a growing theme: that the men are hotheads, while the women are capable of being more measured. I have no idea in grand terms where the story is going but that’s one possible direction.

Which actor is the least like their character?

Matthew Macfadyen for sure. Matthew himself is decorous, well-read and charming – but his character Tom is such a doofus.

What’s your favourite role in your career so far?

Oh gee. Well, I love this one but outside of Succession, I adored Juno and the Paycock in the off-Broadway production. My part in Rectify was fascinating because she was so repressed. And I loved my role in my husband’s movie Margaret, which was incredibly multifaceted – and Kieran Culkin was in it too, which brings us full circle.

Your Twitter game is excellent. Is it a chance to show your political side?

I suppose so. I was bashful to begin with, then Brexit and our election happened. I felt like everybody suddenly had to become political to some degree. Maybe it was too little too late but it was time to find a voice and connect with people. The global community felt in danger and it felt like social media could be used for good. It’s also fun. There are a lot of witty people on Twitter.

What makes you happy when you’re not working?

I’m a big bookworm and love to read. I like baseball. I’m currently looking at colleges with my daughter too, which is gratifying.

You should dress as Gerri when you visit the colleges.

Good idea! I might command some respect.

Succession season 2 continues on Sky Atlantic and Now TV