You build an arrangement, not a romance
What your mind is like is Capricorn; where it gets used is the 7th house — and together they turn closeness into something constructed. You think about a partnership the way you think about anything durable: what it is for, what each side supplies, whether it will still stand in fifteen years.
That produces relationships of real solidity. It also means the early stages of one are conducted by you as an assessment, which the other person can usually feel and rarely understands.
Respect is the requirement, not affection
You can survive a great deal in a close bond and you cannot survive not respecting the person. Once competence, judgement or seriousness has gone, no amount of warmth substitutes. That is worth knowing about yourself, because it means the qualities you should be selecting for are not the ones the situation tends to foreground. Ask what they are like at work and how they behave when something is hard.
The feeling exists and is never mentioned
Your commitment is expressed by what you build and maintain, and the sentence that would name it does not get said, because you assume the structure speaks for itself. It does not, to most people. Say the plain thing once a week. The building was never a substitute for it, and the person inside the structure has been waiting a long time.
Terms first, feelings afterwards
You want the practical questions settled before the emotional ones: who is responsible for what, what happens if it goes wrong, what each of you is actually agreeing to. Others find this unromantic and it prevents most of what destroys long arrangements. Have the conversation early and say why you are having it, so that it lands as seriousness rather than as caution.
You do not enter these lightly
A close bond is a commitment you intend to keep, so you are slow to form one and extremely reluctant to end one. That reluctance is honourable and it keeps people in arrangements years past their usefulness. Set a review rather than a threshold: once a year, an honest assessment. Ending something you built is not a failure of character, and treating it as one is the specific trap here.
Carrying somebody has a physical cost
When the person closest to you is struggling, you take on the practical load without discussion and without reducing anything else, and the strain shows structurally: a tight back, ground teeth, a stretch of poor sleep you attribute to work. Name what you are carrying, at least to yourself, and put something down. Endurance is not a plan and in this position it is the default one.
You commit properly or not at all
There is no casual setting available here: either the relationship is a serious undertaking or you are not really in it, and the intermediate stage feels to you like wasted time. Say that plainly rather than performing an ease you do not have. The people who want the same thing will be relieved, and the ones who do not were never going to work out.
You are somebody's designated serious person
In each of your close bonds you occupy a specific function: the one called when something has actually gone wrong, the person whose judgement gets asked for on the decision that matters. That is a position of real standing and it runs almost entirely in one direction. Ask one of them for something substantial this year, so that the relationship has been tested both ways before the day arrives when it needs to be.
Put the business arrangement in writing
Working partnerships suit you well and they need documenting, particularly with people you like, because that is exactly when nobody wants to raise it. You are the person who will do it if it is going to be done. Draft the terms and present them as ordinary practice rather than as distrust. Every arrangement you have watched fail was one where this conversation was postponed.