Take the keys with you.

"Are those the only keys you've got?", you ask. He nods. Without saying another word, you turn around and walk away.

"hey! What are you doing! I told you these are the only keys I have. I can't get out of this thing without them." he complains while following you in your room.

"Isn't that exactly what this stuff is all about? Someone else holding the key, deciding when you get out and have an orgasm?" you ask, turning around and looking directly into his eyes.

"Well… Yes, but…" he stumbles. "Good, then shut up and find some sleep" you tell him with a soft voice while closing the door of your room right in front of his face.