If it’s still bothering you after you’ve slept twice on it, it’s probably worth bringing up.

Time is a decent filter for what matters. Most irritations shrink overnight, which is why the standard advice is to sleep on it, and the ones that survive two nights are telling you something real rather than something reactive. If it is still there on the third morning, letting it go is no longer the cheap option; it is the one that quietly builds up.

Let it have two nights, then say it in one plain sentence to the person it concerns. No build-up and no audience. Most of what people regret not saying would have taken thirty seconds.