Confront the problem when you’re calm and they’re alone. Same words, completely different outcome.

Onlookers change what a person is able to do. In front of others, someone has a reputation to protect, so even a fair point becomes something they must push back on. Alone, the same sentence is just information they can take in. Your timing and your setting decide whether they get to hear you or have to defend themselves.

If something needs saying, wait for a moment when it is just the two of you and you are not still angry. Walking somewhere helps, because nobody has to hold eye contact. Say the thing plainly, then give them room to respond without an audience keeping score.