Please pick up your granddaughter and visit with her at your daughter's house! Why should your son's rude and childish behavior prevent you from having your granddaughter.
I urge you to allow your son to have the natural consequences of his behavior as his ex is doing. When he's inappropriate it is appropriate that he not have his daughter. Her mother wants to be sure she is safe and not exposed to her father's language and anger.
It's important for you to accept that the issue of your son having or not having his daughter is between him and his ex and should not involve you. I'm pleased that your granddaughter's mother is willing for you to have a visit with your granddaughter. This issue is between you and the girl's mother and has absolutely nothing to do with your son.!!!!!!
It sounds like you are allowing your son to control how you feel and how you act by his rude and obnoxious behavior. You do not need to please him. You are his mother and he owes you respect. YOU hang up on him when he starts in with the foul language. Warn him once, saying that his language is foul and rude and that if he continues using it you will hang up. That is the natural consequence for his behavior. You do not need to put up with it.
I'd continue to arrange for visits with your granddaughter with her mother if she's willing to do that. I'd also not tell your son that you're doing that. It is actually none of his business. He does not have custody of her.
It is natural that you don't see his second child as often. As you said, you weren't a part of her early life. I imagine you often took care of your first granddaughter. This along with her being the first forms a close bond.
Stop trying to please your son! Do what is best for yourself and your first grandchild. Tell your son that you will spend more time with his second daughter when he treats you with respect.
Your first granddaughter needs your love and attention. You are a very important part of her life. Keep seeing her and leave your son out of it.
I keep writing because I'm feeling so angry with your son and frustrated for you and your granddaughter. He is hurting his own children with his rude behavior. Are you hurting your granddaughter in an effort to keep peace with your son? You need to stand up for yourself and your granddaughter. No one has to get permission from her father for you to visit. Her mother is in charge of her daughter's time and activities when she's with her. I don't understand why you'd give up time with your granddaughter. Are you hoping that your son will treat you right if you do what he wants? That's way backwards. You have to show that you respect yourself and therefore make decisions that are in your best interests before he'll respect you. He still may not respect you but you'll still respect yourself and not allow your self to be controlled by an immature temper tantruming "boy."
Later: Did I not understand your question? The original plan was to pick up the 5yo from your son or from her mother? That does make a difference. If you were picking her up from your son, you do need to work at not responding to his anger so that you can pick her up.
There was a time that my daughter and I fought often. I finally learned to just not say anything at all while she ranted. When I found myself needing to defend myself, I ended the call or the visit before my anger got the best of me. It took several weeks but eventually we both stopped trying to control the other one. We were both in a power struggle because each of us was trying to convince the other one that we were right.. When she told me how to take care of her daughter, I just listened and said ok. Usually what she requested was what I'd do anyway. And if it wasn't what I'd do, it wasn't so important that I had to do it. She rarely asked me if I did what she said but when she did, I said that I had.
I want to add if you were going to pick her up from her Dad, that I also urge you to do what you must to spend time with her. I also urge you to be the first to hang up on him when he gets unreasonable. Never argue with him. The same rule that applies in parenting children applies when dealing with adult children. Never argue. When you argue you lose your standing as an adult and are stooping to his level. You are better than that.
I'd "eat crow" if I'd been you. Say the words even tho you don't mean them. I've not had to do that with my daughter. She was quick to anger and quick to forget that she was angry. But I would have if it was necessary to see my grandchildren. She needs you to provide some stability in her relationship with you. She doesn't know that Daddy made it difficult for you to be with her.
I also think that not going is a good plan too at this point. You do not have to put up with his disrespect. He has to know that you won't.
You can consistently provide natural consequences for you son when he is disrespectful while at the same time learning how to manage him so that you can spend time with your grandchildren.
My daughter also felt that I played favorites. I did see my granddaughter more often because my grandson, who has a different father, spent time with his father. The way we handled that was for us to plan time for me to be with each one. Planning the time helped alot. Once I started spending more time with him I realized that I did favor my granddaughter because I didn't know him very well.
Once I realized that I consciously am sure to pay attention to both of them. When I buy one a trinket during a visit, I make a point of buying the other one a trinket during their visit.
This would be more difficult for you since you live 3 hours away. But when you visit you could plan to take each one alone for a specific period of time. That might help. And always be sure to pay attention to both. It's much easier to pay attention to a 5 yo who is more socially mature than to a 1 yo who is still a baby.
In summary, do not give him what he calls bs. Hang up before he gets to you, before you feel that you have to say a word. Picture yourself as more mature and capable of maintaining a calm conversation when he insists on fighting. Just hang up. And don't pick up the phone when he tries to call back. Call back yourself the next day or so.