Watching the Dark (2016)

A film about cinema presented as a psychological domestic drama. A married couple, Martin and Sara, control each other through voyeuristic means while subjecting themselves to the same influence. Sara's sister, Karen, is perpetually trapped as an unwilling spectator. When Karen visits them following the end of an unrequited relationship with another woman, their inability to show any empathy sends her spiraling towards a nervous breakdown. Their marriage begins to disintegrate when Karen's struggle disrupts the way Martin views Sara.