Sorry this is long.
I've been on and off with my partner for 2 years. I'm due our first child soon and he has a 3 year old son with a previous partner. They split up when she was in early pregnancy and she went on to have many sexual relations with other men and eventually got into a long term relationship with a man who was at DSS's birth and DSS was taught that was his dad. They have recently split and she is seeing someone else, having yet another father figure around her young son which must be confusing for him.
She has constantly messed OH around with contact arrangements and him paying money. He now is lucky enough to see him twice a week, for 8 hours in total (including the hour and a half MIL has to drive to pick him up and drop him off again). She gives him the times the same morning and if he isn't there for that time then she fucks off out with DSS and her new boyfriend. She demands £100 a month off of him (he doesn't earn much and they don't go down the CSA route) and then she asks MIL for money for other things, so gets around £250 in total. She lives with her parents so doesn't have to pay bills and everything is provided for her son by them so I imagine she just spends the money on booze and fags anyway. MIL has her on Facebook and from her photos and statuses she goes out drinking a fair bit so DSS is left with his grandparents a lot, when he could be with OH.
He is moving in with me shortly to save money and she has said DSS won't be able to visit at our house, he has to visit at his grandmas (MIL's) and that this will never change. So that means when baby is born we won't be able to have them together unless I go to his mums with him which is a lot of effort as it's an hour away from my house. I understand that she may feel threatened by OH having another child but she will be depriving DSS of a relationship with his half sister
. Anyone else experienced something like this? I'll be a first time parent and step parent so finding it hard to cope