kuyo-kuyo
Dwelling on something negative that already happened. A mental loop of regret that's hard to break out of.
💡After saying something rude — 'Stop going kuyo-kuyo over it, it's done.'
過去のことをくよくよしても仕方がない。
There's no use going kuyo-kuyo over the past.
Don't ___ about what you can't change.
変えられないことを○○しても仕方ないよ。