Also on the topic of wills, I have for example added that I want my daughters to directly inherit my jewellery. Even if you have a will that you inherit each other as spouses, you can still specify.
Should something happen, I know they will not be left by chance to some wicked step- mother .
You never know what could happen…

Sadly in this country there is no such thing as a protected child’s part in inheritance. In some other European countries a child has the right to receive a minimal share regardless if in a will. You can’t disown a child.

In your case, it’s worth asking your dad about it. If he doesn’t sort anything out, if he marries her she’s stands to inherit everything should he pass away first.

I think its not up to anyone you all geddy people thinking of money Really why??

I completely side with your suggestion that English laws should change. In many countries the children (all children) inherit by default a percentage of the estate.
People are very fragile towards the end of their life and are too easily manipulated.
My 82 year old uncle spent 3 weeks in hospital about 2 months before he died, where a 70 year old former nurse cared for him who made him change his will and he left everything to her. My family couldn’t even get the family pictures and other mementos back.

It’s utterly normal for any parent to want to leave money and family possessions to their children, and it’s also absolutely normal to make sure that their spouse is well looked after. So it’s not greedy to assume that something might come your way. But where’s the right balance?
I agree with those who’ve said you should have a conversation. In my professional capacity (mediator) I often blog about this - the importance of talking to one another while you can, to avoid future difficulties. If you say nothing (and try to readjust your own feelings), that might be fine for you, or you might be left wishing you had. If you do choose to say something, then be frank about what you want to understand, but (as others have said) don’t let him feel you have any expectation (or resentment about his new partner). If you have any particular needs (or worries) then tell him - he’s your father - but the decision will always be his.
When working out how to have a conversation, it’s often better to ask open questions (what/why/how) than make statements or ask yes/no questions, so you can hear him explain his thoughts in his own words rather than just react to your words. It might be an ongoing conversation, or over in one sitting - he alone gets the final say on his own wishes, but it’s important that you can speak openly to him if you want to.
I wish you the best of luck.

OP has my sympathy, this is a relatively common and very understandable situation, but I've no concrete suggestions.

I don't agree there is anything fundamentally 'entitled' about expecting to receive some inheritance from a loving parent, although I think there are good points made above about not relying on this financially. But to me the main thing that comes across in replies here is how hurtful it is emotionally if children are left out of a will, for whatever reason, careless or otherwise. And this is far more likely to happen with the complications of merging families.

But the OP is in an impossible position; if you don't mention it, you may regret that later, but if you do, you risk destroying your existing relationship with your father and stepmother-to-be who could resent what they perceive as your greed and unwarranted interference. In a similar situation, I got sucked into a corrosive and destructive debate after my father invited me to the solicitor's appointment to plan his new will and then didn't act on the advice. It's taken years to patch up the relationships subsequently and that was only because I backed off and suppressed my true feelings of rejection at his decisions. So be very very careful, even if you think you're in a family where you can talk to each other about anything.

If you feel you have to say something, my suggestion would be to broach the subject in an abstract way, alone with your father. Definitely not by email. In the context of saying that you're happy for him, mention that family rifts can occur with these extended stepfamilies over money issues and inheritance and that you hope he will always be careful to be sensitive of that. Then leave it at that. Do not get into a discussion of what might be 'fair' or what he plans to do, even if he starts to offer suggestions. And then try to let it go, to preserve your own sanity (you have no control over his choices and less influence than the stepmother will have), and focus on all the positives for the family - of which thankfully it sounds like there are many. 

I can't believe people think they're entitled to their parents money so much so they factor in an inheritance and feel they should talk to their parent about what they do with THEIR money.
If my children are like this I've failed as a parent 😔

This is a delicate subject and one which i have very recently been part of and been very hurt by. My stepfather who raised me from age 4 fell terminally ill. I didn’t want to ever speak to him about his will because I thought that would be direspectful to talk about such a crude topic and part of me felt as we were truly close ( I loved him dearly; He was my mentor, someone i hugely looked up to, my friend and I considered him my parent as wevlived together at home growing up throughout schooling,teenage years , into my late 20’s when i moved out after Uni) we often spoke ended our calls with a sign off of i love you. He would say you know i love you too. His illness was kept from me by my stepbrothers and i was searching for answers and help as to why he was so ill but not getting any better which was so distressing during covid lockdown as i had no access to fly to him. When he was acutely ill he finally got a diagnosis as i pleaded with him to get another opinion from another hospital and within that week he knew it was terminal. I was devastated but again didn’t want to broach the subject of his will and money. After spending his last heartbreaking few weeks in hospital by his side, I found out his sons inherited his estate with nothing mentioned about me . They have not even had the decency to speak to me about any of this despite 1 living in the same borough as me. I’m sure they are at peace however, A year later to this day i am still hurt and confused and I really feel collusion ocurred as my stepfather’s illness went to his brain. I have no other words than for my stepbrothers who grew up being schooled in public school in another country- What you put out into the Universe comes back around. I know i am innocent in all of this but very confused. I do wish i had spoken to my stepfather about this if only to understand. I would have accepted if i knew this is truly what he intended. It just doesn’t sit right.

Absolutely have this conversation. We were in this position some years ago, failed to do so and the end result was that following the deaths of my father and his new wife in quick succession, everything went to her children. My parents would not have wanted that.

I think we should be pushing for a law change in the UK to move to a situation in which the interests of the children of the first marriage are automatically protected when an older person re-marries. I think that the default position should be that the new spouse retains a life time interest in an estate but that on their death the children of the first marriage should automatically inherit 50%. The parent could write a will changing this if this is what they actively wanted but the children of the first marriage would not find themselves left with nothing because their parent had not understood the situation and/or just not got round to writing a new will. 

English laws on inheritance are archaic,in my view. They do not seem to reflect the increasing number of second marriages which take place when one of the partners is very old and susceptible to pressure. For those who say “it is their money and they can do what they want with it”, I agree. But in many of these older person second marriage scenarios this is not what is happening. Either the old person does not understand that the marriage revokes earlier wills or they think they will get round to it but do not, or they are actually pressured by predatory new spouses who do understand what the stakes are.

When my mother died she left considerable sums to my father which had come from her work and her family. She would have wanted him to enjoy them during his lifetime, but she would be spinning in her grave if she knew her own children had ended up with nothing. 

I’m not sure there is much you can do to be honest. My father-in-law remarried in his 50s to a woman with two adult children (my husband was my father-in-law’s only child). Before he died a few years ago, he’d transferred all his (considerable) assets to his wife and there was nothing legally that my husband could do. Thankfully he had never counted on getting any inheritance so nothing materially changed for him.

My advice would be not to count on any inheritance whether or not your father remarries. You have no idea what might happen in the next few years. My own father had to go into a care home - sadly he was only there for a year before he died but with fees of >£7k a month (and they’d be a lot more now) if he’d been there for a while there wouldn’t have been much of his estate left - and there were long term residents who’d been there for ten years or more.

Never ever factor inheritance in. There are so many reasons that it might not happen. He might spend it all or use it in care fees or live to a very ripe old age. It is his money, not yours, to do with as he wishes. You could gently ask him if he intends to make a will (because marriage revokes any previous one) but I think more than that is overstepping.

Oh Lord, yes, you must speak to your father about this.

My brothers and I were in a very similar situation a few years ago and we made the mistake of not sorting things out before he died. Following his death, we went to court to challenge his final will and it tuned out to be very expensive, hurtful and high profile, splashed across the front pages of the nationals. Eventually we had to settle as the only true winners were the lawyers and the stepmother, as naturally the odds were stacked in her favour. As well, it sowed rancour and fallout amongst us brothers, such that I haven't spoken to one of them for more than 15 years.

Not sure if there is anything to do here but thought that I would ask in any case. My father, a widow, has started to make noises about making his relationship with his partner more official. She is lovely and makes him very happy all of which is great.
I am absolutely delighted that he has found happiness but a part of me is worried about mine and my sister's inheritance. His partner is younger and has 3 children. I am trying to be the bigger the person but I keep coming back to wanting to speak to him about it but not sure how. It is his life, money etc. but I know that my sister and I have sort of factored it in to our futures. Can we, should we say something?