However cute aggression is a form aggression and even when expressed in the most benign way possible, it can hurt.
The difference between aggression and cute aggression is that cute aggression is not out of control in the way someone might think of when someone loses their temper. It can be controlled by the person who is experiencing.
Perhaps cute aggression is a way of saying there is something special in the relationship between the two people that includes no one else. It’s another way of expressing that the bond is too special and unlike any other.