A sexual act including a saddle and/or table tennis paddle
guy 1: we got so far last night
guy 2: what base
guy 1: 12th base
guy 2: Woah!!! how did u get a saddle into her car
To defy the laws of physics whilst engaging in sexual intercourse.
A common example is to have sex listed as the 'Bat Position' in the karma sutra, and that is to have sexual intercourse on the ceiling.
I went to 12th base last night and i got such a rush to my head.
Fucking a chick so hard that she dies.
Man 1: Ah shittt man, I fucked Cindy so hard, I got to 12th base!
Man 2: FUCK! Where is the mangled-sexfilled-corpse?
Man 1: In my car where I left her...
Man 2: I say, go for 13th base
Man 1: Ahh, wanna munt her with me?
Man 2: YEAAHHHH, I'll jump.
Giving foot and or boob jobs with 2 or more people.
Dude, last night i got to 12th base with this hot chick and her twin sister!