Can you forget?

Dave starts talking to two women in a bar. They turn out to be identical twins, and they wind up back at his apartment where they have sex in a torrid threesome.

When they finished, one of them sees a violin and says, "Is that a violin in the corner? I'd love to play the violin for you while my sister sings."

So, both naked, one sister plays the violin and the other sings for Dave who is laying on the bed completely enthralled.

A few weeks later, the girls are walking past Dave' apartment building. One of the girls says, "Let's stop up and see that guy."

The other girl says, "Gee... do you think he'll remember us?"