Resolve the issue without becoming another issue the relationship later has to resolve.

How you conduct a disagreement can create damage larger than whatever you were disagreeing about. The thing said in anger, the week of silence, the point pressed too far. Then there are two problems and one of them was entirely manufactured in the handling.

Keep an eye on the method, not only the outcome. Ask whether you could describe your own behaviour in this next month without wincing. That question, mid-argument, prevents most of the lasting damage.