About this scene
Public park, early afternoon, with joggers visible through the trees in both directions. They're behind a low retaining wall but not behind cover. He's behind her, she's leaning forward against the wall, and the audio picks up a jogger's footsteps about thirty seconds before the finish. Neither of them slows down. He pulls out and finishes loud across her ass. She turns her head sideways and lets out a single short laugh. The jogger keeps going. He never breaks stride.
What to watch for
Listen for the footfalls in the audio. They're consistent and they're getting closer. About forty-five seconds before the end you can hear them clear in the right channel. The cumshot lands eight seconds before the jogger passes. Watch her face after she laughs. She's looking right at the path, tracking the jogger by sound, and she does not break eye contact with that line of sight even once. She wanted to know if he saw.