I have experience breaking up with people and being broken up with. The latest experience was being broken up with, and it gave me great insight into how not to do it to someone else. Granted, that didn’t make it any easier being on the receiving end of a confusing “but I still love you” style of breakup. Granted, the situation was complicated to begin with, but that really doesn’t excuse confusing and ultimately hurtful behavior.
So, if you’re going to break up with someone:
Don’t agree to anything that you would only do with that person if you were in a relationship together. Don’t be like “maybe we can go get coffee in a little bit and see if things work out” unless you intend this to be taking a break instead of a break up.
Don’t say “I’m doing this for you” because you’re not. You’re doing it for YOU. If the other person wanted to break up with you, they would. You are not doing them any favors by assuming that you are helping them in some way.
Don’t try and be nice
It’s going to hurt no matter what you do. Yes, be polite. Tell them “it didn’t work out” instead of “you’re a complete jerk” — unless you want to tell them they’re a complete jerk, of course. But then you’re not trying to be nice anyway. But if your instinct is to not hurt them, the best way you can do that is simply by being honest and polite. Say “we don’t have the same style of humor” instead of “your jokes always make me cringe” but say it nonetheless.
Answer their questions
They’re going to want to know why. You don’t have to answer, of course, but I think it’s a fair question and they have a right to know. Try and be polite, but don’t give them the impression that it’s something they can simply change and you can get back together. Unless that’s what you want — but then it’s an ultimatum, it’s not breaking up, and you should phrase it as such. Depending on the situation, they might have other questions, such as things that you said earlier that are now inconsistent with your desire to break up. I think it’s only fair to answer those questions, too, to the best of your ability. Of course, you don’t want to drag the process out, but you also don’t want to leave them hanging and confused about what you really want or mean.
And that’s what this all gets down to, really. You don’t want the person you’re breaking up with to be confused about whether you’re breaking up or taking a break or giving them an ultimatum. Your job is to make the process as simple and clear as possible. And if they say they can’t see how this is “really breaking up” then for God’s sake believe them and come up with some other way to phrase it that does sound like breaking up. Because otherwise you’re going to think you’re broken up and they’re not and you’re going to hurt them way more than is necessary in this situation.