Place it at the end of an argument scene, after the other person's line has finished, as the closing reply. Follow it with a buzzer for a game-show verdict or a scream for an exaggerated reaction, then cut to the next scene before the moment drags.
About this sound
This three-second clip has Richard Benson saying 'vattene affanculo per cortesia' in a sharp, irritated voice, with the polite ending landing after the insult. It feels rude, funny and deliberately formal at the same time, like a dismissal dressed up as good manners. The contrast is what makes it land as a meme insult.