AITA for refusing to help pay for my sister's kids' college education?

My wife and I have two children, my sister has three (1 male, 2 females). Obviously, her son will get my share of the estate. I love my two kids enough to want to leave them a good sum of money. I do not love my sister's kids enough to want to leave them a large sum of money. I do, however,, believe that it is right for me to help pay for their college education. I am not paying for their food, their entertainment or their tuition. However, I do feel that I should pay for their tuition. <br><br>Here is where I am an AH. I refuse to have any contact with any of my sister's children until they graduate from college. I do not want to build any bond with them. My sister says that this is unfair as she feels that it is unfair that I am ignoring them. I told her that I completely respect that they are here and that they are her children. But I am not paying for them to have every experience they want because they are here. If you want to take them to the zoo, that is fine. I am not going out of my way to spend hours with them. I do not want to build a bond with them. <br><br>I am a relatively young man. I have two children and I want to enjoy life with them right now. That is why I bought a jet ski for my son (his dream) and a ride on lawn mower for my daughter. That is why we are going on a weekly father-son trip to our local Bass Pro Shops. I am not devoting those kinds of time to my sister's children. I have no desire to. <br><br>AITA?