Place it at the end of a relationship scene, after a romance cue has set up the couple, so the rejection closes the scene. Follow it with Dun Dun Dun to underline the fallout, or with SpongeBob Fail when the edit is meant to stay comic rather than serious.
Über diesen Sound
This clip is a short spoken breakup line, delivered in a flat, weary voice over just under six seconds: 'I just don't love you anymore.' The delivery feels cold and final, with no anger or pleading to soften it, which makes the rejection land as quiet and awkward rather than dramatic. It works as a blunt emotional punch for a scene that needs an abrupt ending.