This was the first movie I thought of too! I saw it when it was released in an art house theatre. I didn’t know much about it, and apparently most of the audience didn’t either. Once the film got to that scene where the guy buys a teen boy magazine and climbs into the back of the car to…you know….a bunch of people just got up and walked out!
Yeah... that's the first moment when the mask starts to slip, and you realize you're in for something entirely different than what it initially appeared to be.