A joke

In the Creative writing class, we learned the structure of jokes. That was mine:

The knife in his hand set loose. He has never threatened a woman before. He could end up in jail for that.

“DO IT, MARK, DO IT,” Luke dared him.

“Okay”, Mark yelled, squeezing the knife tighter and lifting his chin up. “I will.”

Every step to that dark alleyway felt like his last one. He felt like he was going to his own execution. His boots became heavy, they didn’t want to leave the pavement. His steps shortened until he completely stopped, hiding behind the skip.

He didn't need to wait for long. A young pretty woman, in a shiny cocktail dress, knocked her heels past the skip.

Mark stepped in front of her, the sharp steel looked like an extension of his hand. “Strip down real quick,” he said, raising the knife.

She didn't say a word and lowered her tights.

"And the rest," Mark said, unbuttoning his shirt, then his pants.

As soon as her sparkly dress touched the concrete, Marked grabbed it. Quickly he pulled it on and ran away screaming, “Luke, we're good! I've got the dress!”