I think you are jealous of a three year old; don't want to be three again but wish you had the relationship with your dad that the three year old does. I did that with my nieces, even watched my eldest niece get slapped when she "wanted" my stepmother, her grandmother, more than her own mother.

You and your dad are at different places now, both in life experiences and time. I'm sorry your father could not hug and play with you and give obvious signs of love to you when you were your nephew's age, but that is not a reflection on you or your father now!

Do you want to just wish your father had showed his love for you more then, or do you want your relationship now to be better? Talk to your father about his life when he was the age you are now, how he coped with X, Y, and Z problems and what his life was like when you were young; get to know your father as a person instead of just thinking of him as a "father" and how well you think he did in that role for you. He is a grandfather now, that's a totally different role; he doesn't have the worries of raising your nephew, getting along with your sister or brother as a spouse while trying to make a living and a home at the same time.

If you don't want a relationship with your nephew, don't want to learn to relate to a child (good experience for having your own children; you think you'll "love" them like you think your father did not you, but where's your practice and experience doing so? Did you father get that practice anywhere before you came along? Obviously not.) then go to your room, the bathroom, the basement, somewhere he isn't and do something else if you feel bugged by him. Relationships are both choice and hard work. Because someone is a parent does not mean they "chose" to be with their children, their actions show that. It sounds like you and your father do not have a true relationship, but it is not too late if that is what you want to work on for yourself. You can't make your father participate but you can open communications to find out if he'd like to work on having a relationship now too.