My partner and I have been together for 3 years and he has two girls from his previous relationship ages 11 and 14 who we normally see every other weekend. I have always got on amazingly well with both of them and felt they really respected me. However this has all changed since my partner and myself have had a new baby. At first it was just a few snotty remarks behind our backs to other family members but now the baby is here it's worse!
The tipping point for me was Christmas. Firstly when they arrived they did not even acknowledge the baby. Wouldn't even look at him! This made me furious they were sat on the sofa right next to him! It's obvious their mother has told them not to interact with him.
Then the kids and my partner were playing a board game and I was trying my best to settle baby down to sleep. The game was still going on at 11 at night and I was still trying to settle the baby as they were all shouting being load and keeping him awake. I must have told them 10 times to be quiet. Eventually I firmly told them to go to bed as they couldn't be quiet, got sniddy comments in return. 
My partner and I consequently had a huge row as he says I have no right to tell them off and he says he doesn't want to do it himself as he doesn't see them very often and doesn't want to spoil the time he does spend with them. He also says them having fun is more important than the baby getting sleep!
My point here is what on earth do I do? I honestly feel like I no longer want them in my home but then again am I just being selfish after all they are just kids and also my sons siblings!
Or do I say to my partner from now on you see them else where? My baby can't be disturbed every time they are here just because they don't want to be respectful.
I also look after them occasionally on the weekends while my partner is working which I am not comfortable doing any longer. I am so worried this is going to cause a massive issue in our relationship and am so torn about what to do.
Any body else had this sort of reaction from step kids towards new siblings? Any advice would be very welcome.