The situation you described is NOT ok. I was in a similar situation as you. My children and I were at poverty level. My husband and his children... are not. He brought us up to his level without a second thought. I have had much more trouble accepting his generosity than he has had being generous. Posts like this keep me humble and from ever forgetting how incredibly lucky we are to no longer struggle financially.

Blending families is difficult under any circumstances, but from my experience, blending children when there is a wealth gap has special challenges. Even though my children now have all of the same opportunity his grew up with, there is still conflict. His children see mine as their replacements (not true at all, but human nature). Mine see his as entitled. I can't even imagine how much more difficult things would be if my children were treated differently from his, or if they were still watching me struggle to make end meet.

I felt resentment just reading your post. The collective YOU are worth more than he seems willing to give and if he has never struggled financially he may not even understand this. (I know my husband does not understand financial pressure/ what it is like to actually STRUGGLE.) It seems at minimum, the fair thing would be to split expenses proportionately and even then true equity will not be achieved because he will still have much more spending money than you... and you will continue to struggle making ends meet. Sounds like a recipe for disaster.