Your Sisters Sister review

Struggling to cope with the death of his brother, Jack (Mark Duplass) agrees to spend a week alone at best friend Iris’ (Emily Blunt) island cottage. No TV, no internet, just him. “Do they have forks?” asks Jack. “Because I have to stab myself in the face.”

But he arrives to find Iris’ lesbian sister, Hannah (Rosemarie DeWitt) already there, doing her own soul-searching having just split with her long-time girlfriend. When the evening starts, they’re just two people shooting the breeze – and a bottle of tequila. Six seconds later, they’re two people who just had sex. Sure enough, Iris’ surprise arrival the next morning completes the setup.

But Humpday writer/director Lynn Shelton’s indie relationship micro-drama is so natural, affecting and funny (“I really think your face is going to annoy me right now”) that nothing feels calculated.

Shot and cut with invisible style, Shelton’s movie lets the trio’s semi-improv performances push and pull the drama effortlessly. Mumblecore dude Duplass is mischievous and edgy, throwing nervous looks and cheeky darts of wit.

Blunt is bright and wonderful as the girl in the middle. Rachel Getting Married star DeWitt takes a role that’s bending towards cliché – a vegan lesbian who’s “emotionally allergic to butter” – and reinforces it with careful complexities. So it’s a real shame, then, that Your Sister’s Sister stretches a little bit too far for its own good.

Having drawn out the drama with such humour and subtlety, the movie’s third act rings surprisingly false to leave it feeling as weird and unrealistic as Humpday .

Luckily, Duplass, Blunt and DeWitt have already won us over, and their witty, believable interplay is what stops this three-hander feeling like a throwaway film. Makes you wonder what they could do with two bottles of tequila...