Parents pressuring me to spend time with nephew.

My parents are constantly asking me to spend time with my 3 year old nephew. I used to play hockey and now he’s starting to show an interest. They are constantly pressuring me to go on the ice with him or play with him in their basement when I come over to visit. I haven’t gone on the ice with him yet. Mostly because I am very busy and my weekends are spent doing what I want to do. I also have my own child and it just seems outrageous to me that I’m being asked to spend so much free time with my nephew when I have a little one at home. My parents are constantly guilting me about not helping my new here with hockey. How do I get them to stop?