Am I an asshole if I cover my sisters art with spray paint?
Why do you want to cover your sisters art with spray paint?
I think it's unattractive and would be an improvement if I covered it with paint.
I know you have strong opinions about your sister's art, but it's not right to destroy it because you don't like it. Your sister has the right to make her art and not care what others think. If you don't like, you shouldn't look at it.
Hmm I guess you're right, eh.
Instead of covering up someone else's art, why don't you create your own piece from scratch? You might be a great artist and I'd love to look at your work.