What makes a couple durable is not how rarely they argue. People who study couples for a living tend to point instead at the hour afterwards.
Whether somebody makes two cups of tea. Whether the joke gets attempted. Whether one person crosses the room before either has fully cooled down.
The argument is loud and the repair is nearly silent, so we remember the wrong half. If this week held a bad exchange, the strength isn't proved by never having another one. It is proved by who moves first tonight.