Divorce Support Forums: Need some advice

Just when I think that things are on a good footing with my friend/roommate's stbx, life shows me how fragile that footing is.

I've been staying with my friend now for a year. His stbx hasn't ever really liked me and that was okay for me but it made things hard for him, with her constantly giving him ultimatums coupled with threats of taking him to court for full custody. Things finally settled down a bit at one point last year then got rough in March, when she told him she didn't want her children being left alone with me. When I asked her to talk about it with me, she basically attacked me verbally. It left me upset but not willing to walk away.

In April, he asked me to please take over the finances because he was having a hard time getting the money to last through each paycheck. So I took over, cutting certain things down to the bone and making sure that certain bills were paid on time so there were no late charges. Since then, it's been hard but there have been times when it was possible to have a luxury or two, like ordering pizza.

For most of the last year, she lived on the proceeds from the sale of their house, adding in his child support payments, an amount they agreed to after working with a mediator when they first separated. She also had a live-in who contributed somewhat. She had to move almost a year ago because of water damage. Her current residence is more than she can afford but she has a roommate who pays part of the expense. She also finally got a job, which meant that there is now the expense of daycare for half a day with the youngest child, 2 hours with the oldest. They're both under 10 so it's unwise for them to be alone together at home for 2 hours as yet.

He has told her that it's impossible for him to pay her more money than he already is. Doing his finances, I can tell you it's already hard for him to pay what he pays, and he increased it voluntarily $100 three months ago.

Tonight he came home and told me that he needed an accounting of the money situation, that she believes he can pay her more money monthly. She has it in her head that his bills went up a lot when I moved in, that his paying for those increases means he can pay her more, and that any money I've brought in has been gotten illegally.

My question to all of you is this: Does she have the right to tell him what to do with his money after he's paid her the support they agreed on? Can she force him to pay her more just because she thinks he can afford it?