When my grandparents sleep, I'm going to cut their laundry.
What did they do to you? Why would you want to cut up their laundry?
I think my grandparents deserve the stress.
If your grandparents are annoying you, you should talk to someone about that. You shouldn't go around destroying people's belongings because you want to cause them stress; that's just cruel.
No one here cares about my grandparents.
Do you think that's fair to mess with your grandparents then? How are they going to feel knowing their grandchildren doesn't like them either? I really believe your relationship can get better, just keep initiating conversations and try to find things in common instead of destroying their things.