Twelfth Base 

Fucking a girl so hard she dies.

Steve: Man I fucked Katie so hard last night that she died while cumming.

Aneesh: Really, twelfth base? How was her funeral?

Steve: I got to thirteenth base at it.

Twelfth Base by Steve from Canada (1) February 4, 2010

twelfth base 

WTF ARE THERE EVEN THAT MANY THERE ARE ONLY 3 IN BASEBALL

guy a: dude, i did it w/my gf
guy b: how much?
guy a: twelfth base
guy b: wtf

twelfth base by subscribe to me on youtube pls May 8, 2018

twelth base 

the action of sniffing & sneezing, when you put your nose up someones back passage and sniff in the delightful aroma, then sneeve, unbleliavable pleasure.

"dude, i totally went to twelth base last night"
"dude, really, what even is that?"
"dude, she totally snotted up my ass"
"sweeeeeeeet"

twelth base by sniff&sneeze February 11, 2010