How to break up
It can't be that hard, right?
There's nothing easy about ending a relationship, but sometimes tough calls have to be made and there comes a point that you have to tell her that it's time to go in different directions.
You can't control how she's going to respond to the news, and you can't control how her friends will act on social media. But it's worth having a bit of a plan so that you can try to minimise the emotional pain that you're both going to have to navigate as you transition out of the relationship.
Don't be passive/aggressive
This may be happening subconsciously but it's surprisingly common. Even before you've articulated to yourself that the relationship is over, you start unleashing negative behaviours that provoke dissent. You're effectively trying to force her to break up with you, so that you don't have to do it.
Not only is this dynamic miserable for you both, but it's much more damaging and hurtful than if you just had an honest and up-front conversation that you're ready for a change.
Don't cause drama in public
Public breakups are messy. Why are you having the "it's not you, it's me" chat in a cafe or a bar or wherever.
Subconsciously, we're hoping that having other people around will prevent the emotions getting out of hand, but it's disrespectful. Let her have her feelings. Breakup conversations should be had in private spaces.
Don't leave her isolated
She's going to want to reach out to her friends or family or at least be somewhere where she feels safe. That's why breaking up when you're away on vacation somewhere is a bad idea.
Don't jump off a cliff
Not literally, obviously, but if you're walking out the door then you need to have thought about what happens next for you both. What will the housing situation be for both yourself and for your (now ex) partner? Are there any shared financial aspects that will need to be sorted out?
If it's going to be complicated, you probably want to avoid surprising her with a breakup. You might need to look at some couple's therapy to help talk about how you're going to work together to bring the relationship to an end.
Don't make empty promises
In the emotional highs and lows of a breakup, we tend to say things we don't mean - anything to try and get to a place where you leave and put this behind you.
If it's not just a temporary break to "figure some stuff out" don't tell her that it is. If you don't want to share custody of the cat, then don't promise that you will. If you say something like "I'll call you tomorrow to see how you're doing" then you need to make that call.
Also, don't lie. If the reason that you're breaking up is that you've met someone else, you may not need to volunteer that information but if she asks you: "Are you leaving me for Susan?" then you need to address that head on. If you lie, she will find out, and then that makes everything worse.