I am a big believer in spousal money being "ours" not mine or yours.
I think it is a HUGE problem that DH is consulting with Mommy about how to spend the spousal income, rather than with his Wife.
I think that THIS was what was triggering "Hey, she is the one that is working, not him!" for many of us (certainly me) rather than that he was a full-time student.
It is like he is treating the spousal money as his money.
Agreed. He is using the family money for something HE wants to do. It would be akin to him taking a chunk of the family money and buying a mountain bike, or Playstation, or whatever benefits him, but not so much the OP.
I would not think that "fulfilling a family obligation" (which is what the OP's husband probably views this as) is in *any* way analogous to him buying a Playstation, or something that benefits only him.
Because my husband's family obligations are my obligations as well.
And tending to those family obligations benefits me, in excellent relationships
with the extended family.
My DH and I have to negotiate so that we see these situations or obligations the same way. But there are times when he says, "This is our obligation as a family (which we are--a unit, one family) to our larger family." I don't agree; but he knows his family, and I trust him.
And I do not consider that to be a selfish or frivolous move on his part.
I don't think the MIL is being appropriate, nor is the DH necessarily right.
But this is not the same thing as him taking the family's money and buying a Playstation.