You shouldn't try to pet someone's dog without their permission.
Max is walking down the street and another person's dog approaches him wagging it's tail.
Max wants to welcome the dog he sees.
Max verbally greets the dog and smiles at it.
Max decides to pet the dog without the owner's permission.
The dog continues wagging it's tail and Max waves the dog goodbye.
The dog bites Max on the hand and Max cries out in pain.