Jane Schoenbrun tends to exhaustively shot-list their movies, arriving each day on set with a rigorously formalist philosophy of filmmaking. But in the making of their newest feature, the director had no real plan for the sex stuff. This was odd since the erotic-signaling title, Teenage Sex and Death at Camp Miasma , had been rolling around in Schoenbrun’s brain for years — and the story itself was, in the director’s own words, “about learning how to stop dissociating during sex.” Turns out, this necessitated a meta lesson behind the camera. “I realized once we got to production that I had been really avoiding, if not dissociating, from having to direct those scenes,” Schoenbrun says now, in their first in-depth interview about Camp Miasma . “Directing those scenes felt as scary as it felt directing for the first time.” Premiering as the opening Un Certain Regard film in Cannes before Mubi releases it in theaters Aug. 7, Camp Miasma hardly feels like a first film.…