Should you go?

I just learned that my ex husbands father passed away. He was my father-in-law for 7 years and Ive known him for 20, yet I have no desire to go and pay my last respects. Its not that I disliked the man. He was a great guy. However, while I was raising my kids, and his son was failing to pay me child support, he took HIS side. I guess that's what you are supposed to do with your children, even if they are in the wrong. I just cant get past it. Every time he and his wife would come to visit the boys, I always got a sob story about how much money Kevin didn't have and how the DA was making HIS (my ex's) life miserable. HELLO...what about OUR kids? I can remember one thing in particular that left a knot in my stomach. My ex in-laws took my kids for the weekend. While they had them, my oldest sons shoe broke (Well, ripped is a more appropriate term). Instead of paying 10 dollars and getting him a pair of shoes from payless, they duct taped it and sent him home that way. In their minds, not only is their son in dire straits because he has to pay child support (poor, poor Kevin) but they arent going to dish out a dime to buy their oldest grandson new shoes just to spite me, even though they knew I wasnt getting money from him because he was unemployed at the time. My mother would NEVER have done that. I don't feel sorrow for the man that just passed away. As a matter of fact, I don't really feel anything. I know that he was my children's last grandfather, and I want them to pay their respects, but I don't thinks it my job to make sure he gets to the funeral. Steven, my oldest, is in the military so he wont be able to make it. I just think it should be my ex husbands responsibility to find a way to take my youngest son. I know he doesn't live here and when he flies in, he wont have a car or money (what else is new), but for once he needs to be the one to figure it out. Am I right? I cant afford to take a day off work to attend the funeral. What is the protocol for something like this? Am I supposed to attend out of respect for my kids?