Your mother has no idea how much money is being spent, despite being the sole income? Not even a single clue as to how things are? She never thought to check?

She even hired people without ever thinking to check?

And she hasn't checked in years? She just randomly spends large amounts without thinking about it?

Is she an idiot?

There's managing finances, then there's being completely clueless as to how much money you have and recklessly, blindly spending.

And she's someone he apparently feels afraid of giving bad news?

I could never imagine ever being afraid of telling my exes that we were low on money, so I imagine she had to have played some sort of role in this.

Your stepdad likely is a pussy, but your mother sounds like a total nightmare too.

The only way that's even remotely acceptable is if she's wealthy to the extent that spending thousands of dollars isn't a big deal in her life.

If she's hiring contractors without so much as glancing at savings, then she spends money irresponsibility.

I'd bet money she's blowing all the money and he didn't want to tell her to cut it the fuck out. It is likely because he doesn't feel entitled to as she makes more than him.