You feel Kurt's hands grab your waist with one hand, and then feel the tip of his cock teasing your asshole.
(start rubbing your ass with the head of your dildo)
Steph: "oh, you probably can't wait for this, can you, Katie. You're about to become a real slut. Kurt, show katie what a real cock feels like."
(start to slowly fuck yourself for 5 minutes)
Steph: "It hurts at first, but as with all gateway drugs, you'll soon be hooked. Speed it up a little."
A moan of pleasure escapes your mouth
Steph: "Wow Kurt, maybe when you are done with Katie you can have some time with me. Katie can clean up for us after."