AIBU to think I'm not a terrible person for leaving my terminally ill partner?

Why don’t you defend yourself? The British are fundamentally the people of “mind my own business” and “drop the rope”. If you don’t tell anyone then I don’t think anyone is going to come asking. That’s not the culture we are. I’m saying this because I think being private in this case is you choosing for you to have no friends left.

if you never open up you never give people the opportunity be there for you.

Leave now. You've nothing to feel bad for.

Tell everyone what he's done. Don't make yourself the bad guy. It might be a bit humiliating but why are you covering for him?

Why are you bothered what his daughter thinks? It's highly unlikely you will see her after he dies anyway. You have only been with this man a short time. You keep coming up with excuse after excuse not to call out his behaviour. Stop being a doormat.

You know perfectly well that I’m not talking about his teenaged daughter. I’m talking about the mutual friends you’re mourning the loss of.

When you responded to those messages, what did you say? Did you set the record straight? If not, then why not?

I wouldn’t send screenshots to anyone but if it comes to it remind him that you have them, and maybe show them (in person) to people who don’t believe you.

But don’t allow this man to get away with it. You can wish him well (because he’s ill) and put the truth out there to those who approach you, you can do both.

You don’t have to send screenshots in order to defend yourself. Couldn’t you say “After the 7th infidelity and finding out he had asked another woman to marry him and all after I had been paying all of our expenses so that he could pay the other woman’s rent, I am done. I am sorry for his health problems but it isn’t my business anymore”.

I wouldn't necessarily start with posting the screenshots, but instead just let people know the truth.

Defend yourself, see if he confirms or denies and lets people continue to abuse you.
If he's going to deny it and lets people continue to abuse you then you can later post some screenshots.

I think going to the group gossip is a very good idea. I understand there are cultural differences at play here but I think you need to work out which is worst - losing all your friends or speaking up in some way?

You also don't necessarily need to address what happened outright. You could say something along the lines of 'these situations tend to be more nuanced than they initially appear' or something along those lines? This would not be an unreasonable way to respond to his daughter too.

Tell everyone exactly why and don’t hold back

Isn't that even more reason to speak out?

YANBU to leave. Enough is enough.

Personally, I would defend myself but in a very restrained and dignified way, either on the social media posts or in response to the nasty messages. Something like, "You'll all appreciate that there's another side to this story." And leave it at that.

His daughter isn't your problem.
Her father is a pig.

Unfathomable to have such low self esteem to be protecting him still.

You desperately need to do the www.freedomprogramme.co.uk

If you don't want these losers to be whom you attract.

Forget about him and his health.
Hd has made a complete tit out of you and used you.

You deserve so much better than this.

I don’t think I’d be so dignified as that, honestly. I’d be saying something like “This is all very manipulative considering the real reason I left you “therealveryverybadperson” don’t you want to tell anyone about the screenshots I received?”

Nah I’m petty. I’d post that you are leaving him due to numerous affairs and him stealing from you therefore you do not have any feeling left to make you become his carer.

Yes. Absolutely.

hes using his illness to be the innocent one.

don’t let him gaslight everyone into believing you’re the bad guy

Reply to private messages. Act surprised that he is saying that you're breaking up with him. Point out that he has proposed marriage to someone else, he is the one ending your relationship. His lies are going to cost you some friendships, you have nothing to lose by telling the truth.

7 affairs in 3.5 years??

that’s absolutely insane, I can’t even comprehend that.
late 50’s and 19 year old is vile - how old are his children???

also, why wait until the new year? He can leave now.

Recruiting the Gossip in the friend group is the right move. A strategically planned woe is me over-sharing pity party will get this ball rolling

Personally I think you should be making it clearer to mutual friends now. But if you are really determined not to then I would do a couple of things

1. Ask him not to post on any professional type sites like LinkedIn otherwise you may need to make comments on these posts to make things a bit clearer (he doesn't know you dont want to)
2. Come up with a neutral phrase to respond to people or clarify with people. Something like "Yes it is very sad that Xxx has this illness. Our breaking up is nothing to do with that and I would just like to assure you that there are other reasons behind this"

Something of that ilk that points at the bigger story.

You need to tell people he has cheated on you repeatedly and after the most recent affair you had finally had enough and his actions which led to the break up occurred before the diagnosis.

Being ill doesn't make him any less of a prick.

I'm sorry but I haven't read every post, so maybe this has been mentioned. Do you have any reason to believe that he would stay with you if the medical roles were reversed? "Convenient" or not, you have no reason to stand by and nurse someone who has treated you so poorly. Take your money, take your house and let him pay the piper at the end of his life. It seems like that is what he deserves.