103rd base 

The act of anally fornicating with a woman whilst she is in the process of giving birth, and then ejaculating on the newborn. This woman does not have to be your wife.

Guy #1: Hey man, I got to 103rd base last night!

Guy #2: Nice man!

Guy #1: I know, right? I'm being sent to prison, but I have pictures if you want some!

Guy #2: They gave you jail time? Is there even legislation on that?

Guy #1: Pretty sure I'm just about to get to 104th base.

103rd base by Dancup November 8, 2009

143rd base 

When you make love passionately while saying the letters 1, 4 and 3 slowly into your partners ear while fucking him / her so passionately that if you were to watch your own sex tape it would make you cry as if a relative of your has just passed away in a tragic accident

"Omg BRO i jsut got to the 143rd base and i watched over and over again i probably went through about 14 boxes of tissues it was so hot."

143rd base by mica orcullo August 1, 2008