I'm not going to take the dog for a walk even though my grandma asked me to.
Why won't you take the dog for a walk?
I am too lazy to do it.
If your grandma asks you to take her dog for a walk, you should take the dog for a walk. It won't be a long time and you would be helping her out.
Fuck, she is old so it doesn't matter.
It does matter. She is supposed to be able to depend on you when she can't do things on her own. It is your job to walk the dog.