A Deep Breath
A Chinese man arranges for a hooker to come to his room for the evening. Once in the room they undress, climb into bed, and go at it.
When finished, the Chinese man jumps up, runs over to the window, takes a deep breath, dives under the bed, climbs out the other side, jumps back into bed with the hooker and commences to repeat the performance.
The hooker is impressed with the gusto of the second encounter. When finished, the Chinese man jumps up, runs over to the window, takes a deep breath, dives under the bed, climbs out the other side, jumps back into bed with the hooker and starts again.
The hooker is amazed as this sequence is repeated four times. During the fifth encore, she decides to try it herself.
So when they are done she jumps up, goes to the window and takes a deep breath of fresh air, dives under the bed… and finds four Chinese men.