My own brother is a feckless waste of space. When he split from his ex-wife, he did have 50:50 contact, but when he met his now wife, she was insanely jealous that there were 2 other children, both older than her son that she made life VERY difficult for my niece and nephew, and my ex-SIL.
The kids got some GCSE results on Thursday (niece has been in Y10, nephew Y9) and it was down to ME to pass on the information to my (not so D)B. Apparently, he sent friend requests to his kids on FB and they both independently told me that they had declined on the basis that his wife doesn't like them, or want to know them, and when they did meet her, and contact continued for about 2-3 months into my brother's marriage, they (bro & wife) weren't very nice to my N&N, allowing the resident child to access anything in the kitchen, toys, TV remote, etc, while they couldn't do anything, had to ask even if they wanted a glass of water, a piece of fruit and even to use the bathroom, and on the few occasions they stayed over they had to be up by a certain time, but not too early, while their step-bro could lie in as long as he wanted, and had a cup of tea taken to him every Saturday and Sunday morning. It didn't take long before N&N made it clear that they didn't want to go back to his house anymore.
My ex-SIL remarried about 18 months after her divorce and her 2nd husband treats my N&N the same as his own son who is 8/9 years old, is a great dad, and I sincerely wish HE was my brother instead. 
Unfortunately, my dad supports my brother's version of events since 2001, when they divorced, ignoring the fact that my bro was violent, abusive physically, emotionally, mentally to my ex-SIL, which was all cited and upheld in court. So my dad hasn't seen his GC for about 7 years.
What a fucking mess.