Elderly dad and wife expect me to care for her

Well, they gonna have to drastically change their expectations.
Don't let others, even "loved ones", use you.
Noone else is going to put you first, apart from yourself.
Harsh reality of life.

I am unable to provide the care you and your wife need. You can employ a professional carer to provide the help you both need. I cared for my mother and this was 24/7. I cannot care for two people or even one person now. I will contact social services to alert them to you both needing care. You can also ask your wife’s family for care.
As you and your wife know my mother gave her all to bring me up and did so on her own financial means. This work ethic is something that I also have and my time is taken up with working to provide for my family. I therefore cannot take your calls and messages during working hours or during my time with my family. I will call you once a month for a catch up. Regards

Go no contact. You owe them nothing.

Please promise me you will give them nothing. Don't you dare OP! :)

Also how did your DF support you to support your DM during her long illness and support you in your grief?

He had many other opportunities over the past 50 years to make amends and support you if he believed he fell short or made a mistake when you were a child.

He did not support you or your mum when he left to live with his new partner. You owe him nothing. Tell him what you have told us - if necessary by email if that suits better - and that you will not be giving him the care he did not give you. Actions have consequences and he left your mother to struggle whilst pretending he didn't have the means to help. What you sow, you reap. He's made his bed and now its uncomfortable he still has to lie on it. Tell him so.
So sorry about your mum. My DM died last March. I still think, 'I must ring mum' then realise she is not there to phone.

I agree with what has been said before and I think the wording of the message suggested by @5foot5 and by @OnceMoreWithAttitude are excellent. If you decide to use the wording by OnceMore, I'd make one small adjustment to it (in italics and bold below):

“Dad I can see you and DW have increasing need for support and I think we need to be realistic. I had xx years of looking after Mum and know how big a job it is. I need to be honest, for all our sakes, and say I can’t and I won't take on what will become an even bigger job for the coming years. So let’s make sure you have the right support. I can do one day a month helping with xyz. Have you got a Macmillan Nurse? You will need to Let’s look into attendance allowance and getting someone once a day to help with showering / cleaning / cooking / gardening (whatever is needed). “

Put the responsibility back on your father and his wife. I liked the comment that even an asshole with cancer is still an asshole that someone upthread made. It's very true.

You need to accept that this time, you're not going to put yourself through the wringer simply because this person donated some of their DNA to you and then buggered off. I would approach it in a very similar way to how he abandoned you and your mother and can I say she seems to have done a stand out job rearing you to be a considerate woman, one who is grappling with a dilemma like this and I'm sorry for your loss. Only answer the messages/texts/calls when you want to. Work to your timetable. Don't feel guilty at all. You have nothing to be guilty about.

I have thought about how to handle this situation when it arises with my very shit father.

I used to think I will do absolutely nothing but now
I have decided that while he is a shit person I am a nice person. I will help him as much as I think appropriate/ manageable at the time and no more.

they are shit so felt no guilt/ remorse abandoning us . I will feel guilt and remorse and don’t want that.

I also think this is a perfect response. What level of support would you offer to a distant elderly relative ?

Phone them fortnightly to have a chat, during which you can helpfully suggest other solutions for any practical issues that have arisen, but don’t get sucked in.

It’s very telling that your mum, who had sacrificed a huge amount to care for you as a child, did not expect you to support her to this level because she cared about you maintaining your own life as well as caring for her.

You’re in touch with him because you still yearn for the dad who abandoned you as a little girl and desperately want him to step up and change.

That ship has sailed long ago and he chose not to put your needs first, ever.

You owe him precisely nothing in return. You’re an adult now and you really don’t need him dragging you down. You know deep down that he’s always been a selfish prick and I think the time has come to acknowledge this outwardly, block him and move on with your life.

I worked hard on myself following my mother’s death, getting a new job, social life, etc, but I am still deeply affected by the loss.

This is the most important thing. Keep doing all of this. Spend all of your time nurturing your own life - your social life, your career and your friends. Your life to date has been hugely compromised by your DF actions in your childhood and you devoted yourself to care for your DM through her long illness.

This is your time now. Life is precious and short and you reap what you sow - so keep doing all the good things for yourself.

You do not need to defend, explain or justify your life choices to anyone especially this entitled male who seems to see women as functional and around to meet his needs only.

but I am still deeply affected by the loss. - have you had any therapy or support for your loss? Can you take time to read up or focus on that?

Tesco Whoosh is £15, if less than that a £2 charge is added

Even proper Tesco delivery - charge is £5 if under £50 which is cheaper than a taxi or using a car, plus you can get heavy things delivered into your kitchen.

With deliveroo, Amazon groceries and the other supermarkets there are probably other cheaper options as well.

This is perfect. Adult social services, and using their own resources to outsource any help they require. You aren't their staff.

The first thing is to cut down on the messages and calls, as that will remove a huge mental load.

Tell them that you are having trouble with your phone and will be changing the number. Buy a cheap phone that you use only to hear from them and keep mostly on silent or turned off. Block them on your proper number. Be slow about giving them the new number. Check it a couple of times a week. Or less, if you want.

Be far less responsive and much more bland and neutral. Don’t express concern or ‘problem solve’ - when they tell you about a problem or development just say ‘I’m sorry to hear that.’ Or make a practical suggestion about them getting in professional help.

Only give exactly what you choose to do. You owe them literally nothing.

You say no, you are not their carer, have no intention of being one. Other services, when they know of a living relative, often tell service users to ask family for help, pushing issues away from their service. You have no option but to be blunt with everyone.

Sorry OP, this is really tough. Your Mum would be proud of you not jumping up to their every whim I’m sure.

I imagine this ‘Dad buggers off then expects care when he’s old’ is quite a common scenario - if you consider just how many absentee fathers there are. He is obviously deluded.

Dont say 'sorry.' Ever.

Say No.

This sounds very hard and painful too. I can see how you might want to maintain some kind of contact especially as you’ve sadly lost your mum but not wanting to care for them in the way they expect is completely reasonable. My parents are similar to your mum, they ask for little and I do all that I can. They want to put me first as your mum did. I think your dad is putting himself and his wife first as they did so long ago. The suggestions to say you are unavailable at times and answer messages when is convenient are good ones. But I suspect it will eventually lead to some kind of fallout as they will try to guilt trip you and put pressure. I’m sorry if that happens because I know it’ll be disappointing. You sound like a lovely and kind woman and you need to put yourself first. It’s what your mum would have wanted for you.

Stop assuming that when they ring you it's for a valid reason. If there is a crisis and something goes wrong, it's not on you to fix it, or your fault if it isn't fixed. If you believe that it will be much easier to draw boundaries. It's important to address the behaviour directly I think so they understand the issue. Explain that they called you over for something important but it turned out not to be. As a result, you will call over at set times (eg Tuesday evening six-seven). Explain that they need to arrange their own transport to appointments as you are not available. Point them to home carers if need be.

I don't think it's necessary to point out your history together, but if you do I find these things come across best if you're matter of fact and even breezy, so it can't be quibbled. Like if they pull 'you're my daughter, you should be helping us' then say 'when you left me with my mum we lived in poverty. I don't feel any obligation to you but I will help out this much because I am a nice person.' No need to get emotional yourself.

I looked after both my parents in my home and it's nearly killed me. I lost hundreds of thousands in earnings and my own family suffered. I developed a major health condition.
You owe this man and his second wife nothing. She needs help and has her own biological children. They need to step up. Organise shopping but do not put yourself down as medical point of contact. You will get no peace and little help especially if you're single/child free.
Quite frankly it's a bloody cheek as you had suffered his lack of decency in childhood. Blood ties do not make you a slave to these people. He sh*t his nest years ago. Keep saying no.

He wasn't there for you when you needed care as a child - you should do exactly the same for him.

Call them once a month and just ignore their calls - when they ask you to take them to appointments just invent an excuse or forget to reply to their calls or messages.

They'll soon stop trying. How cheeky of them to ask this of you considering how little he cared for you when you needed help and support as a child!!!

You don't need a large shop if is delivered, lots of people have the equivalent of a basket delivered.

Don’t most online supermarkets have a minimum spend charge ?

There are no medals for looking after your dad and his wife and giving up your life in the process. It’s your time to grieve and rest and live, don’t let them rob that from you.

Nope. Don’t allow yourself to get sucked into this. Your dad’s wife’s health is absolutely nothing to do with you and everything to do with him. He’s the one who should be liaising with social care and NHS to get things organised, not you. There are services available, which from what you’ve said, they can well afford. You need to make it clear now, from the start, that you will not be getting involved. They’ve made their bed and the fact that they’ve now had a life event to make them realise that, is not your problem.

I dare say similar has happened in the past. My DM (born 1916 and highly capable) had an old friend of apparently equal intelligence - they’d both held quite responsible jobs before marriage/babies, but once her husband died the friend had no clue about managing anything. During her entire long married life she’d never even written a cheque, or paid a bill. She’d been given housekeeping money every week, and that was it.

And I gather it wasn’t a case of a controlling husband - by all accounts the marriage had been a very happy one. But even my DM found it almost impossible to understand.

But we all should do what we can to future proof ourselves. Unless they are in their 90's excluding disability there isn't really a reason for them not to be able to Google. I know people choose to get 'old of thought' but if you are 90 you were 65 in 2000..

You don't need a large shop if is delivered, lots of people have the equivalent of a basket delivered.