We Are the Flesh

An unknown apocalypse has devastated the globe, forcing siblings Lucio and Fauna to forage for food and shelter in a hostile environment. They happen to come across Mariano, a man who offers them both of these things, but at a cost: they must help him turn an abandoned building into a cave/cocoon-esque structure. He also demands that the siblings have sex with one another while he watches. With few other options the two comply, only for this act to be the start of many strange and horrific things they must do in order to survive.