He puts a collar on you and although you can't quite see it, you think there's a chain attached to the collar. The suspicion is confirmed when a hard tug force you to go forward. He guides you without a word, and you almost fall in the stairs leading to the basement, barely catching your footing. You can't see much under the mask but the air feels way colder here and so you know you're underground, probably with walls of cements.
"Spread out your arms."
You do as your told, starting to regret your choice of signing that contract. He takes your head and without delicateness bend you over a table. A little dizzy you realize he's tying your arms to something. You feel your heart beat faster, as you know what is going to happen next. Rightly so, a few seconds later you feel his penis, moist with lube. You get excited but in the rubber dildo it really doesn't show.
He starts to fuck you, fast. He's bigger than you though and it hurts a little bit, but you've taken guys before and so it's still quite pleasurable. Suddenly he grips your hair and pull you head backwards, and that hurts more. Still you're excited, and you're thinking maybe this was the right choice. You can hear him grunt and you feel a wave of satisfaction at the though of your master being happy with you.
Soon enough you feel the hot cum in you ass, and he stays there for a while, moving his dick slowly inside of you, before taking it out and slapping you on the ass.
You can see anything, but you hear the stairs creak and the door close.