A word can hurt you more if it's from someone you care, even after long time you've forgot about each other. Nobody should know this kind of pain. And nobody has the right to cause it.
Ignore User
Both you and this user will be prevented from:
Messaging each other
Commenting on each other's stories
Dedicating stories to each other
Following and tagging each other
Note: You will still be able to view each other's stories.