Place it just after the reveal in a betrayal scene, following Sudden Suspense to build the moment, then let Sad Violin carry the aftermath once the accusation has landed. That order gives the scene a clear rise, a sharp turn, and a slower comedown for the joke to settle.
Über diesen Sound
This is a spoken clip built around one incredulous line, 'You cuckold'd me!?', running for about eighteen seconds. A single voice carries the question, letting the accusation hang long enough to feel awkward and theatrical. It lands as shocked disbelief mixed with dark comedy, the kind of over-the-top reaction that makes a betrayal sound both personal and absurd.