The Thermostat Peace Talks

Every long relationship eventually becomes a border dispute over six degrees.
One of you is a furnace. The other is a lizard on a cold rock. Neither of you is lying about how you feel, which is what makes this so hard to settle and so easy to keep going.
Admit what is really happening
Nobody has ever changed the thermostat by accident. Every adjustment is a small diplomatic act. Walking past the wall unit and tapping it twice is the household version of moving a fence post at night.
A treaty that tends to hold
- Pick a number you both dislike equally. That is the definition of a fair deal.
- Assign the blanket to the cold party. Our throw blanket has the terms printed right on it.
- Allow one fan. The warm party gets moving air and may not be mocked for it.
- Declare a bedtime exception. Bedrooms are their own country, with their own laws.
When talks break down
They will. Someone will come home to find the house at a suspicious 71. This is normal, and frankly it keeps the marriage interesting. Raise an eyebrow, say nothing, and quietly restore your preferred number when they go to the mailbox.
The only rule that matters is that you both keep showing up to negotiate. A couple still arguing about the thermostat after twenty years has clearly found something worth staying warm for.