Thank you for the welcome, might have to name change to plank instead, I'm beginning to feel like one! (made me laugh) 
In my case I have a DSS Wdigin, it's really his mum and my DP's approach towards her that is making me feel fed up. We (he) has a series of issues that need to be discussed with her about DSS. His eating habits, which are becoming a huge problem at home...refusing to eat, only eating tiny amounts, and often gagging and spluttering during meals. He cannot use the toilet alone, cannot dress himself, and has been reverting to 'baby behaviour'...using a young childlike voice etc.
Once again DP's ex has basically told him just to push along, refusing any discussion about it. On top of this his latest pair of shoes that DP bought have disappeared at his mum's, and his only alternative pair hurt his feet he says. Once again this is nothing to do with her, she threw his shoes away as they apparently no longer fit, the alternative pair hurting my DSS's feet are my DP's problem as she didn't buy those either. She apparently can't buy him shoes, clothes, a school coat or anything really. Just ridiculous.
We're expecting a baby next month and summer holiday arrangements are up in the air. DP would normally have him for the full 6 weeks, but I have already said with my other children and DSS it would be too much to manage, especially as I'm having a c-section at the start of the holiday. So far she has ignored his suggestion of a 50/50 split, and is already sewing the seeds of a future guilt trip.
My DP always says he will talk to her, but in reality he barely speaks and she shuts him down. I'm tired of him being such a pushover, especially as he has little problem critiquing how I parent my children from a previous relationship.