I wouldn’t marry or do CP in your position.
Get LPA in place.
Get your wills sorted.
You can each leave £325 + £175k direct to your kids if you leave them your share of the house (with a life interest to stay living in the house to the surviving partner). But would need to change to owning the house ‘in common’ if you currently own it ‘jointly’.
I see Wills as being for the next 5 years. If you die within 5 years that’s plenty of time for him to marry a new woman who outlived him and leaves your kids out of her
will. Seen that happen so many times.
And yes, if you have inherited your £750 and left it to your Dc there would be IHT to pay, but so would there be if it went IHT-free to your husband and he then left it to the Dc.
Or it might get spent or put into a new marriage.
Bereaved men move on fast and leave their kids’ interests behind all too often.
I realise this is not a nice way to think but marriage is essentially a legal and financial contract, and contracts are for when the nice ways of negotiating fail.
You’ve managed your family life and business as a team successfully on love, commitment and fairness, if it’s not broke, don’t fix it!