Since American Pie reconfigured Porky’s 20 years ago, the modern sex comedy has abided by a tacit formula. Call it the sweetness-to-raunch ratio. It would be completely unacceptable for comedies about woefully inexperienced dudes to be only about their single-minded pursuit of gratification, so it has to be cut with material about friendship or the tender feelings they can access in vulnerable moments. And age is the key factor: the younger the dudes, the more sweetness required. The 40-Year-Old Virgin can be as raunchy as it likes, but the STR ratio changes with American Pie and Superbad, which have many more scenes of teenage boys bonding over their shared ineptitude or treating girls with kindness when no one is looking.