In the movie Social Network, there is a scene where Sean Parker corrected a sentence said by a girl who he just spent a night with:
She was rather astonished when she realized the man standing in front of her was Sean Parker so she wanted to double confirm, "I just slept with Sean Parker?" Instead of replying her with a yes or a nod, Sean Parker said, "You just slept on Sean Parker." And he laid stress on the word "on".
Sean Parker: I founded Napster.
Amy: Sean Parker founded Napster.
Sean Parker: Nice to meet you.
Amy: [Surprised] You're Sean Parker?
Sean Parker: Ah ha! You see, the shoe is on the other...
Sean Parker: Table. Which has turned.
Amy: I just slept with Sean Parker?
Sean Parker: You just slept on Sean Parker.
Is there a different between "slept with Sean Parker" and "slept on Sean Parker"? What is the significance of emphasizing on the preposition "on"?