One child has inherited AGAIN

The only option is to leave your assets to your oldest only. Would you though?

if not, no point dwelling just accept they have an uneven playing field and life is inherently unfair.

Sorry, just to be clear, you tried to convince your partner to change his will and leave more money to his step child than his biological dc? That is pretty nuts if so.

Your family is blended but your kids do not have one family. They have two. Personally, I think they should inherit equally from your household, given the older won’t inherit from his dad, but it’s fair enough if grandparents want to leave money for their biological grandkids only.

This happened in my family, one family had four kids only two of whom were the genetic kids of the son who had predeceased. All the beneficiaries agreed to sign a deed of amendment to redistribute. Might not be what a lot of people agree with but felt right to us. That was decided by the adults though, I've never asked the two youngest whether they felt cheated.

Your partner isn't your older son's biological father ? He doesn't have to leave him anything at all but intends to?
I don't think you are reasonable to think your partner should in some way be responsible for evening out the balance. That's just life, I'm sorry.

What can you do about it? You could choose to distribute your own assets differently between your two sons.

Your older child wasn't her grandchild, and has his own paternal family to inherit from. He won't have counted as a male member of the family, because in terms of bloodlines he isn't.

It’s difficult but same will be true for my 3 children. Eldest has a different father - youngest will benefit for their grandmothers large estate. Only thing I can do is leave my house to DS1 only, DS2 and DD will be fine with this, and as he won’t have DC, likelihood is he will pass to his younger siblings anyway (he is 16yrs older). It is what it is, and I am not going to feel guilty. I am separated from father of DS2 and DD so I certainly won’t be benefitting either from that side of the family.

Is the son who has inherited their blood relation and your elder son from another relationship? (Sorry if this is in the post- I couldn't quite grasp it.)

Oh that’s tricky! To be fair to your MIL, her skipping a generation may be more about avoiding two lots of potential tax etc, rather than avoiding your (existing, different dad?) older child. The half brother thing with the male heirs is very peculiar though!

I know you said you can’t make up the amounts, but it would be perfectly acceptable to address this with your own will and make up whatever difference you can - and of course be very open with them both about what you are doing

How old are your children. Will your younger DS give some to his older brother do you think?

Mils brother sounds horribly sexist. I wonder what the families with daughters as well as sons feel about it. They are in a similar situation to you with ds1.

unfortunately there’s nothing you can do but it’s sad for your ds1. Are there any members of ds1 biological family who he might inherit from in future?

Sadly there's nothing you can do. They obviously didn't see your elder child as part of the family.

How old was dc1 when you met your current partner?