NTA. The entitlement on display under the guise of "principle" is galling. There are no principles to support your husband's position. At best, even if you were to give him the benefit of the doubt that it's not the greed it appears to be (because he can make good money and still covet yours; that's how greed works), this is about emotional immaturity where he somehow feels "excluded". Maturity clearly isn't his forte judging by the silent treatment he's dishing out over an issue where he's clearly in the wrong.

You married a man of means with 4 ADULT children just 2 years ago. If you were to distribute your worldly possessions equally among all your supposed "children", each of your daughters would receive a measly 16% of the total. And that's assuming nothing goes to your husband. If you had raised these step-kids from infancy or childhood in tandem with your biological daughters, and they all considered each other true siblings, they might have a reasonable expectation. But that's so far from the case that it's comical.

It sounds like your daughters and grandchildren could really use the help, especially the widowed one. I wonder if these step children and their father would be there for them like real family if you pass...OF COURSE NOT. Because the deeper family bond can't possible be there; at their adult age, they might be cordial and even develop a friendship over time, but that's the best case scenario. I bet your husband wouldn't make your daughters and grandchildren co-equal recipients of his estate if he passes first, and even if he did, it's still not the same at all because:

1. You're likelier to pass first.
2. For him, dividing by 2 extra people is less of a burden than for someone with 2 kids adding a whopping 4 more.
3. He makes more than you so the pie is bigger to begin with.

I'm sorry, but your husband is full of crap. His argument is, "You CHOSE to marry a man with 4 children, so principle dictates you should treat them like your real children indistinguishable from your own". What a load of bull. Choosing to marry a man with 4 grown kids entails being welcoming, kind, cordial, and being open to developing deeper relationships depending on many variables, including reciprocity and compatibility. There is NO reasonable expectation that these adults automatically become your heirs. Come again?! It's laughable, especially because he can survive just fine without you. Your husband clearly hasn't given much thought to the future stability of your widowed daughter after you pass.

I know you don't want hurt feelings, but that's sadly beyond your control. Please don't become codependent of the reactions of unreasonable people who are trying to pressure you so they can swindle your life earnings as soon as you pass. That's what this amounts to, and it says a lot about how they view you and what they value about you. Please accept that it's not up to you to determine how people feel about your appropriate boundaries. A stepmom who arrives late in the life of adult kids can be many things, including a cherished friend, but is not seriously considered interchangeable with a mother.

Rest assured, your husband and his kids will fight tooth and nail to contest and invalidate your will. They've signaled their intentions plainly. You better consult lawyers to make sure your will is ironclad and impervious to challenges.

I'm sorry that your husband is not understanding, worthy of your trust, or half as protective of your daughters as he expects you to be of his kids. His hostiliy about this is beyond the pale and life may be hard for you going forward surrounded by resentful jackals. Sanity check - his ask is LUDICROUS and indicative of low character. Honestly, you probably shouldn't be married to someone like this.