I moved my grandparents' laundry into the trash while they slept
Why would you put your grandparents clothes in the trash?
My grandparents didn't like the way I lived and they were critical of my work and social habits.
I am pretty sure that they still wanted their clothes. You should not touch things that do not belong to you, especially if you are just going to throw them away!
It's fine. They are old and can get new clothes.
I just don't think there was any reason to throw them away. You should get their clothes out of the trash.