I'm sorry you're so frustrated and hurt. That situation would be hard for anyone!
Perhaps you should bring up asking for a custody change for different reasons. You make it sound as though Mom isn't doing her job, as a parent. A child that overweight either has some emotional issues he's "dealing with" by overeating; or he has abominable eating/exercise habits at his primary residence. But if you make it sound, to your DH, like you just want him to stop having to pay CS, he may interpret that to mean you resent spending money on his son. He may especially interpret it that way, if he wishes to avoid thinking about the good sense in other things you're saying (like not buying $50 jeans when one of you is out of work). "She just doesn't want any money to go to MY kid!" is much simpler and easier to combat, than the other issues surrounding his kid.
I don't know that spending equality ought to be a goal, in a blended family. At birthdays & Christmas, yes. I think you & DH ought to budget very similar amounts for gifts - and for parties - for each child. What other people - parents, grandparents, WHOEVER - are giving the kids should not factor into this. The kids have unequal situations in other relationships in their lives. That's a fact that cannot be remedied or hidden. But the magnitude of the gifts they get from YOU GUYS is equal.
In terms of other spending, it may be better to assess what each kid's needs are and try to figure out how to meet them, on the budget you have. For example, in our blended family, my ex is wealthy and his wife is kind of a shopaholic, so they buy a lot of things for our kids. My DSS lives with us. His Mom lives far away and doesn't pay support. This is how we've handled some issues:
> Clothes: Sometimes money is pretty tight, for us. I have no problem with hand-me-downs and second-hand shopping. I do care what each kid likes. I just think, if you like this article of clothing - and it's in good condition - should it matter whether I bought it new or second-hand, or whether your brother wore it last year? Not when someone else (your parent/step-parent) earns the money for your clothes and everything else you need!
Twice a year, as I put away off-season clothes, I make a pretty anal inventory of what each kid needs, for next year. (How many outfits appropriate for school; appropriate for dressing up; appropriate for getting muddy outside; pants and T's to sleep in; different kinds of jackets and shoes, etc. will it take, for that kid to get through a week of school, church, extra-curricular activities and playing with friends, with me not having to do laundry more than once a week? Because it takes a week for me to wash clothes and linens for 6 people!) Then, throughout the year, I assemble what each kid still needs, from good deals I find at stores; second-hand shops and garage sales. Although each kid has clothes at their other parent's house, I feel like what I put away for the season - at our house - is a good approximation of what's available to them, at our house. DSS also gains about 20 pounds every time he visits his Mom in the summer, then loses it over the course of the school year. So, part of my planning is the knowledge that he'll need shorts in one size for the start of school; and pants and shorts in a smaller size, for the fall, winter, and start of next summer. In other words, I never get rid of his "big" shorts, when he slims down. I just put them away 'til he needs them again.
Sometimes, my biological kids need scarcely anything, because their Step-Mom has bought them many things that wind up permanently at our house, so most clothes spending is done for DSS. Sometimes, my biological kids have a growth spurt and need a lot; while the hand-me-downs DSS gets from them meet most of his needs, so I buy him a few new (or new-to-you!) shirts/sweatshirts/sweaters he'll feel excited about but most of the shopping is for my bio. kids.
In our case, all three kids leave for school every morning, from our house. But if one of them only got dressed here every other weekend, naturally that would affect what I felt that child's clothing needs were, at our house. On the other hand, if that child's custodial parent weren't providing him enough clothes, that might factor into my assessment of his needs, too.
Things are straightforward for me, because I do all the clothes shopping. But if DH wanted to do some of it, I have a specific list I could give him, of what each kid still needs at any given time. If your DH is going to do the shopping for his son, it is not unreasonable for the two of you to agree, in advance, on how much you have to spend - total - on back-to-school clothing; and for you to be clear with him about what all that budget needs to cover - for ALL the kids. If such restrictions ACTUALLY make DH want to divorce, then perhaps this is a relationship that can't be saved. But I suspect he would grudgingly get with the program, if you matched his overspending on DSS's clothes, with spending cuts in other areas of your family budget - areas DH would notice. ("Sorry, honey. When we buy $50 jeans for the kids, it cuts into our beer money...")
> Extra-curriculars: My bio kids run cross-country, which means decent running shoes (which sometimes their Dad buys); an overpriced team sweatsuit every few years; and a yearly participation fee. But, other than that, they need some running shorts and junky T-shirts, to practice in. DSS does sports AND plays an instrument. We simply never compare the spending, on each kid. We just pay for what they need, to pursue their interests. And if we can't afford it, we look for alternatives. Can we rent an instrument from school, instead of from a music store, or buying it? Or, registering DSS for intramural baseball costs half as much in one neighborhood league, as it does in another.
> School: Last year, we spent tons more on DSS's education because we decided the most appropriate school for him was a Catholic school, while my bio kids were in public. Again, no sense comparing it and trying to make it equal somehow. Just address each kid's different needs.
> Technology: My bio. kids (the twins) have some vision- and fine-motor-related challenges and are allowed to use assistive technology in school. So they have Neos (word processors) and Kindles (with their textbooks loaded, so they can magnify the text). This did not make us feel like DSS needed to receive similar "cool" gadgets. (DSS did decide he wanted a Kindle, but it was a birthday gift.) However, when the vision specialist at the twins' school offered to get them iPads this year, I refused. iPads offer no educational advantage over the Kindles and Neos the twins already have. And it would make DSS understandably jealous. Plus, our teenagers shouldn't feel entitled to technology DH and I can't even afford to provide for ourselves. If it helped them in school, OK. But even the vision specialist said the main reason she pushes the iPads is that the kids get so excited about using them. Sorry, but so what? I'd get excited to drive a Porsche Cayenne, that doesn't mean I need one!
Hope this gives you some ideas of how to balance "fairness" and addressing each kid's needs, which are different in ANY family, but especially one where the kids spend different amounts of time at your house!
Edited by VocalMinority - 8/19/11 at 3:23am