Even though Derek didn't have to answer Stiles partially-voiced protest, he did anyway.
"You're not being punished," he clarified. "You wanted to be restrained...there's not many options for that in this room."
He crossed the room and picked up the restraints from where Stiles had dropped them. "Some slaves prefer restraints...they say it helps them. Others prefer the challenge of keeping themselves restrained on command. We'll try both ways, until you have a preference."