This evening I'm telling him I'm going to leave

[ArtfulBear]

I keep putting it off, but now I just need to rip the plaster off. I have somewhere to go if I have get out straight away (I do not think this will happen, but let's plan for the worst) and a new home which I can move into in a couple of weeks.

Planning to explain that even though I love him, I don't feel the relationship is healthy anymore and it's time to move to living separately and focus doing the best we can for our little boy.

I can do this. The next few weeks will be really hard but then I'll have my own space and can focus on building the loving home I want to live in with my son.

Will it come as a shock to him? Have you mentioned leaving in any way before/ The shock can make people do nasty things. I was convinced my ex wouldnt be physical but he spat in my face when I told him I was leaving and I think it would have escalated if I hadn’t literally ran out the door.

On the other hand, I can somewhat see how it’s reasonable to give someone warning. I would hate it if my partner just walked out

You have done the right thing planning ahead OP. I had no plan when I ended my relationship almost 20 years ago. I then had to contend with his reactions and responses for some time, coincidentally also in the January, a nightmare.
Good luck!

Be careful OP - I have a friend who gave her husband notice that she was going to leave and went away with her parents for a week - when she returned he had obtained an emergency court order preventing her from removing the children from the family home. She wasn't able to leave with them until she agreed to 50/50 shared care.

Well done for getting this far and having a place to go. Don't tell him now, and then still live with him for 2 weeks - it's 2 weeks of living with his bad mood or ongoing abuse or worse he will try and persuade you to stay, and will likely succeed, 14 days is a long time!
What alarmed me in your first post was nearly immediately you mentioned you can go straight away if needed, depending on his response. That told me more than anything that you know yourself this may kick off badly.
Get your other address set up, keep your plans to yourself and good luck, you've made the decision and thats one of the hardest parts!

It's reasonable to give someone warning, if someone is reasonable. If they're abusive, then it is reasonable to take an airplane evacuation approach and save yourself first. Abusive partners have not earned and do not deserve the usual reciprocities that exist in a normal relationship. Abusive pricks can also do nasty things, shocked or not.

She wasn't able to leave with them until she agreed to 50/50 shared care

Why would she demand more than 50/50? I don't understand why he had to negotiate it with her

Where has the OP said he is abusive? He is pass aggressive and a sulker, but she hasn't mentioned any abuse.

I consider weeks (not hours or days) of silent treatment to be abuse but I accept the OP has not said that. My remark is in response to another post who said someone should be told and I pointed out in general that "if" someone is abusive then its not a good idea to tell them in advance.

@justforthisnow I know that. I am just saying OP ( who knows him best) needs to weigh up the likelihood of him being ‘shocked’ at her announcement and the risks . It’s not about being polite and considerate its about minimising risk

Agree completely, I did not mean to single out your post, it was just the most recent one I saw when I sent that reply. My point is that is there is even a hint of risk, then it's best to err on the side of caution, and you are correct, politeness doesnt matter.

From a practical perspective, why tonight? If you work and should be in work tomorrow, will your child be at school - surely it will be very disruptive for you both.

Wouldn't it make more sense to do it on a Friday night so if he does kick off and you need to leave, you can do so without rushing and go to your Mums, he will want to know where you will be living and I think being at your Mums to give you an extra buffer would be good if you need it.

I would tell him the day before. No longer.

Will he allow you to move your child out to a new home? I wouldn't if I were him.

If your home life is too bad to remain living in, that you have to hide a new home and pack in secret. That suggests your dealing with an abusive situation. I would strongly advise you not to tell your ex.

You're not dealing with a healthy and stable person. Trying to minimize the potential risks of surprise once your ex knows you've left- I understand. But the risks when leaving are so high, it's not worth trying to prempt the future outburst.

Sometimes your silence is your protector, just go, silently and quickly and figure out the nitty gritty afterwards. I speak from experience.

Enjoy your new found peace and freedom!

but I feel like leaving behind his back and not telling him until afterwards is dishonest and I'd feel a dick about it.

I've got this vague notion that if I tell him I've applied to rent somewhere and don't go the same day he might not realise I've been quietly working at it for a few months.

Your two statements above are at odds: you would feel dishonest by leaving unannounced and telling him afterwards, but you feel a two-week warning would mean he doesn't realise you actually have been 'dishonest' by organising this for months.

I suggest that it really doesn't matter if you "feel dishonest" at this point. Whilst honesty is an admirable quality in general, it is not necessarily helpful in this situation, and may even be unsafe.
Your priority is wrong, and your thinking muddled (understandably). Don't prioritise being honest. Prioritise being as safe as possible - because ANY man can get unpredictably nasty in a break up like this, i.e. with a child and a shared home as stake.

I'd like to give us the greatest chance of vaguely getting on in the future for DS though.
I think the manner and timing of your leaving won't make much difference in the long run. Either he will be a decent father, or not. The suddenness of the breakup won't affect this.
You are unrealistic in thinking that you and he have a chance of "getting on". The relationship will be dead, and he will most likely, at best, tolerate you for the sake of being a good father and having smooth hand-overs for contact. But that is okay - that is what matters.