Pyramid Of Jokes
...so the brunette gets to the 5th step and laughs, so she could never try again.
...the red head got to the 20th step and laughed, so she could never try again.
...then the blonde got to the 99th step and laughed.
The guy who was going to tell the joke said "why did you laugh, I didn't tell the joke yet".
The blonde said "I know, I laughed because I just got the first joke"!!!