Ending it is one message, not a negotiation
You do not need his agreement. That is the part that keeps people stuck for another five months. A situationship has no exit interview because it never had a contract, which is the one genuinely convenient thing about it.
So: one clear message or one short conversation. You say you are done, you say it once, and you do not build a case. No timeline of his behavior, no receipts, no seven reasons for him to rebut. Reasons invite debate. You are not opening a debate, you are telling him a decision.
Also true: you do not owe him a flaw to point at. “This isn’t what I want” is a complete sentence. You are allowed to end something that is not bad. Plenty of situationships are pleasant. Pleasant and going nowhere is still a reason.
The ugly part nobody warns you about: he will probably be lovely about it. Warm, a little sad, maybe “can we still talk sometimes.” That reaction is not a sign you were wrong. It is a sign he never had to lose anything before now.
Say it once, in your own words
Before you send anything, walk around the block. Ten minutes, phone in your pocket. Not for calm exactly, more so the sentence gets written by the version of you that has already decided rather than the version currently rereading his last message.
Then keep it to three or four lines. Warm, final, no hooks.
The default, when it has been going nowhere and you both know it:
I’ve thought about it and I’m going to stop this. I like you, and I want something with a title and a future, and this isn’t that. I don’t want to keep half doing it. Take care of yourself.
When you asked for a definition and got fog:
I asked what this was and you told me you’re not looking for anything serious. I believe you. That means I need to stop, because I am. No hard feelings, but I’m done.
When you want to say it in person and need an opener rather than a monologue:
I need to say something and it isn’t a big dramatic thing. I’m ending this. I’m not asking you to change your mind, I’ve already decided.
When there is a practical entanglement, shared friends, a shared building, work:
I’m ending the romantic part. I’ll be normal with you at Dana’s on Saturday. I’m not going to text at night anymore and I’d like you to not either.
No “unless you want to try,” no “unless something changes.” Those are hooks, and a hook is an invitation to a three-week negotiation you will lose because you are the one who wants more.
In person, by text, or not at all
The rule people repeat is “always in person, it is more respectful.” That rule was written for relationships. For an undefined thing, match the ending to the actual shape of what you had.
If you saw each other regularly for months, met each other’s people, slept over most weeks, do it in person or on a call. Not because he earned ceremony, because you did, and because saying it out loud to his face is often the thing that makes it stick for you.
If it was mostly texts and late nights, or it has only been a couple of months, a clear message is fine and honest. Sending a text is not cowardice when text was the whole medium. What would be cowardice is fading out and letting him work out that you are gone, which also leaves the door propped open for a 2 a.m. “hey stranger” in six weeks.
If you are genuinely afraid of his reaction, do it by message, in daylight, and tell one friend you did it. That is not overkill. That is just sensible.
One exception worth naming: if you live together, share money, or share a pet, this is not a situationship anymore regardless of what it got called. That is a breakup with logistics, and logistics need a conversation and probably a calendar.
The part where he gets sweet again
Expect a spike. This is the most predictable thing in the whole event and it still catches everyone. Within about seventy-two hours you will get a version of one of these: warm reminiscing, a sudden willingness to define things, a crisis that needs you, or an offer of friendship that is really an offer of the same arrangement with a new name.
Read the offer for specifics. If he actually comes back with “I want to be with you, exclusive, I’ll meet your friends, I was wrong,” that is at least a real proposal and you can decide whether you believe it based on his last six months rather than his last six hours. If it is “I miss you” with no proposal attached, that is nostalgia asking for access.
What to do with the spike: nothing, for a week. You do not have to reply to every feeling he has. Answering the sweet message with a long kind explanation of why you still mean it is how people end up back in it by Friday, softer and more tired than before.
And if he goes the other way, cold, cruel, suddenly telling you it was never serious anyway, believe that instead of taking it personally. People say ugly things when a supply line closes. It is not a verdict on you.
If you already ended it twice
Then the problem is not the wording. It is the twelve hours after sending it, which is where you are undefended and he is one text away.
So build for those hours specifically. Delete the thread after you send, or at least archive it so opening it takes deliberate effort. Mute him everywhere, which is different from a dramatic block and easier to keep. Tell one friend tonight, by name, and ask them to be the person you text at 11 p.m. instead of him. Put your phone on the other side of the room while you sleep, for the first three nights at least.
Then a real number: thirty days of no contact, minimum. Not as punishment and not as a strategy to make him miss you. Because the loop needs a stretch of silence long enough for your body to stop expecting his name on the screen, and thirty days is roughly when that starts to happen.
The moves that quietly restart it: checking his stories, keeping one shared playlist alive, replying “haha” to a meme, asking a mutual friend how he is doing, leaving something at his place so there is a reason to return, and the classic, one last time to get closure. Closure is not something he hands you. It is what you have left after a month of not going back.
If you have done this three or four times, write down what happens each time in two lines, the actual sequence, and read it on the night you want to go back. Your own handwriting is more persuasive than any advice page.
The week after you send it
It will probably hurt more than the length of the thing seems to justify. That is normal and it is not proof you made a mistake. Undefined relationships are ended without any of the scaffolding a breakup gets: no one brings you food, nobody says sorry, there is no obvious permission to be a wreck about a person who was never technically anything.
Give yourself the scaffolding anyway. Tell two people it ended and let them treat it as real. Plan the two worst evenings in advance, probably Sunday and whichever night you used to see him. Keep the ordinary machinery running: food, sleep, work, one walk a day. Grief without structure just becomes scrolling.
Expect the missing to arrive in waves rather than a slope. Day four can be fine and day eleven can be terrible. That is not backsliding, that is how it goes. The waves get further apart, which you will notice around week three, usually while doing something boring.
If he does come back in a month with an actual proposal, you can consider it from a much better seat. You will have proof you can walk, which changes every negotiation that follows.
What you get to keep
You get to keep the fact that you asked for something clear and did not settle for a maybe. That is not a small thing and it is a skill, not a personality trait. It transfers to the next person, and to your job, and to your friendships.
Tonight, do the two small things. Send the message or make the call, then one physical thing: shower, food, walk, sleep with the phone across the room. Tomorrow, put one plan on the calendar for the weekend so the empty night has something in it.
Nothing about this makes you cold or dramatic. You just stopped funding an arrangement that only worked for one of you.