Claim
The first list
What you owe, stated plainly and without hedging.
You owe honesty, including the expensive kind, and specifically a real answer to a direct question. You owe your share of the load as measured rather than as remembered. You owe the loyalty you actually agreed to, in the terms you agreed to it. And you owe her the information she needs to make her own decisions about her own life, which is the one men most often withhold and then file under kindness.
None of those is a feeling and all of them are checkable, which is the point. A man who cannot tell whether he is holding up his end can answer these four in an afternoon, and the answers are usually less flattering and far more actionable than the mood he was consulting instead.
Claim
The second list
What you do not owe. She does not owe you these either, which is the half that gets skipped.
You do not owe her your friendships. You do not owe her a career decision made her way. You do not owe agreement you do not have, and performing it is a lie with a longer fuse than the disagreement would have had. You do not owe the permanent management of her moods as a standing job.
The symmetry is the load-bearing part. She does not owe you the management of yours, and a man who has quietly appointed his partner as the only person who knows anything real about him has handed her a job she never applied for. The Social course on talking to people is about the rest of that problem. For today, just notice how many names are on that list.
Action
State one boundary, which is not an ultimatum
A boundary is a statement about what you will do. An ultimatum is a statement about what she must do. "I am not going to keep arguing after ten" is a boundary. "You have to stop bringing this up at night" is an ultimatum. The first you can enforce on your own. The second requires her compliance and will be heard, correctly, as a demand.
Pick one and state it today in the first form. Short, no preamble, no stack of justifications behind it. Then hold it once, which is where the whole thing actually lives. A boundary you announce and abandon on the first hard night has taught her that your stated positions expire.
If you cannot think of one you would genuinely hold, that is the more useful finding.
Example
Owen went to Steph's parents every Sunday for nine months and resented it from about month three. He never mentioned it.
His account was that she required it. Hers, when he finally asked, was that she had assumed he liked her father and had been feeling mildly guilty about the drive.
What he settled on: two Sundays a month, and he would say which two by Thursday. He delivered it in about eleven words and the conversation took four minutes.
The arithmetic is the part worth copying. Nine months of resentment, built on an obligation nobody had ever asked him for, paid monthly rather than spend four minutes finding out. Steph's summary of the same nine months was that Owen had seemed fine.
Caution
The man who discovers he owes nothing
This is the day that produces the worst behavior in the course, so the failure comes first.
A man reads the second list, acquires the vocabulary, and starts applying it to everything inconvenient. Her sister's move becomes not his obligation. The dentist becomes not his job. He has boundaries now, and what he has actually built is a smaller share of a shared life plus a language for defending it.
The check is the ratio. If today produced four things you have decided you do not owe and nothing you have decided you do, you read one list. Run the first one again and write down the specific thing on it you are currently not delivering. There is almost always one, and it is almost always yesterday's audit.
Aside
The lists are not fixed
Both lists move, and any course handing you a permanent version of them is selling you a rule to hide behind.
What you owe expands with what you signed up for. A child, an illness, a parent who needs collecting at three in the morning: these change the arithmetic, and "I do not owe the management of her moods" is a reasonable position in year two and a grotesque one in the month after a funeral. The obligations are contextual, and the context is not something you get to declare on your own.
So treat the lists as a dated statement of your current position, and expect to rewrite them. If you are still citing this week's version in three years, you have stopped negotiating and started quoting.