Walk away when you have made a real attempt at repair, out loud, on a timeline you both agree to, and your partner would not meet you there. That is the line. Most people searching this at 1am have never had that conversation.

You're standing in the kitchen, staring at dirty dishes in the sink. Again. They've been home all day, and somehow those dishes are still your problem.

Later, they slide close to you in bed with that look (you know the one) hoping tonight will be different. But all you can think about is those dishes.