What is 51st Base?
When two guys each get anally penetrated by 2 horses simlutaneously whilst jacking off their own father's that are licking your sister's anus as she shits all over his face.
Dude 1: I got to 51st base last night!
Dude 2: Dude, you're fucked up
Dude 3: Are you really sad enough to look through all of the definitions of bases until the 51st?