Banshees of Inisherin 's Kerry Condon has only praise for 'Prince Charming' Colin Farrell

For Kerry Condon and Colin Farrell, settling into the role of siblings in Martin McDonagh's The Banshees of Inisherin was a no-brainer. After all, the two Irish actors have known each other since they were teens.

"That was kind of easy to slip into," Condon, 39, told EW and PEOPLE's video studio at the Toronto International Film Festival. She stresses, however, that their offscreen relationship isn't brotherly-sisterly (at least not like the kind we know). "In real life, he's like Prince Charming," she says of her co-star. "He's just a gentleman: very kind and just lovely to be around. He's always asking if you want tea and taking care of you, just lovely. I wouldn't say brotherly, just a gentleman, very well brought up."

Jonathan Hession/Searchlight Pictures

Written and directed by McDonagh, The Banshees of Inisherin follows two lifelong friends (played by Farrell and Brendan Gleeson) who enter into a painful period of detachment when one of them decides to end their acquaintance. The movie has garnered major awards buzz since its September debut at the Venice Film Festival, where Farrell won the Best Actor Volpi Cup.

Condon plays Farrell's super-patient sister Siobhán, who does what she can to mitigate the feud — but the actress knows that McDonagh isn't celebrated for his happy endings. She and the Oscar-winning screenwriter have had a long working relationship over the years, beginning with one of his plays when Condon was 17. The actress says starring in Banshees was a return to those roots for her.

"This film is quite like his plays, so it just felt like a little extension of that, and a natural progression for me as an actress," Condon says. "It felt a bit more mature and a little harder to play. I don't think I could have played it when I was 18."

Due to her familiarity with McDonagh's work both on stage and screen, Condon says she was not at all caught off-guard by the cynical moves the film makes.

"It's Martin McDonagh, so you know it's going to go dark," she says. "If you've read the plays — which everybody should, they're so amazing — there are always dark elements in them, so I was not one bit surprised, to be honest with you," she says. "You're laughing, but you're kind of wondering why you're laughing."

The Banshees of Inisherin hits theaters Oct. 21. For more with Condon, watch our full interview in the video above.

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