Those brief, intense encounters actually rely on emotional shorthand. A shared glance loaded with history, a remembered touch from months ago, a single line of dialogue that cuts through pretense—it's all about using precise, potent details as emotional accelerant. The author can't waste time on ten pages of build-up, so they drop you into a moment where the tension is already simmering. The intimacy feels fast because we're joining at the crisis point, the breaking point of restraint.
It works when the physical act is framed as a form of communication, a desperate attempt to say something words have failed to convey. Anger, grief, longing—these get translated into touch. A story that just chronicles a hookup feels hollow. But one where a character finally surrenders to a kiss after pages of silent, furious attraction? That's intimacy at a sprint, because the emotional groundwork was laid in the subtext of every prior interaction, even in a short format.