Just a little bit of advice for the OP from the other side of the fence….a couple of years after DP and I started living together I got a promotion in work which gave me a big payrise. Our life got better obviously, we were able to do some home improvements, buy a new car, and go on a ‘naice’ holiday. SS’s mum got wind of this, and started accusing DP of hiding his earnings (he’s self employed), and saying that he was scamming her and not supporting SS properly. All because she could see we had a new car and had heard we had a new kitchen and bathroom. DP’s earnings hadn’t changed at all, he earns far less than me, and he still has quite a lot of debts from when he and was with her, so he pays roughly CSA amount (difficult to get exact with being self employed), sometimes this has worked out with SS’s mum getting more than she is ‘entitled’ to, sometimes a bit less, but all in all over the years it has probably all washed out in her favour, and DP does buy extras as well when he can afford it. We keep our finances completely seperate.
He offered her a small increase to keep the peace, she went to the CSA cos she thought she would get more. It took months of stress for us dealing with there queries, and eventually she was given the same as she was getting before! So all that stress for nothing, and it damaged the relationship considerably – not to the extent that someone describes above re not being in the same room etc, but things are not as good as they were.
She didn’t stop to think for one minute that perhaps it was me that had increased my income, and I asked DP not to disclose any of my financial affairs to her, as it’s none of her dam business.
If she had come at it differently like ‘I’m struggling, SS needs X, X and X, can you help out / increase payments, the outcome would have been much better for her. Effectively it would have been me that would have funded it as DPs finances are pretty stretched each month anyway, but I would have been happy with that if I felt comfortable that it was genuinely needed to feed and clothe SS etc.
So I think what I am trying to say, is don’t make any assumptions about who earns / pays for what in their household, and what you therefore believe you are entitled to. Much better as some of the others say to make it about your child, and what they cost to bring up, why you need more, as opposed to being entitled to it.