This is done by holding your arm close to the side of your body, and inserting the dick in the armpit area.
Scott: Man were you pitting her?
Brandon: Yeah you know it!
Jacob: Your my freeking hero; I always wanted to pit Natalie.
The word pitting is a gerund, meaning it acts as a noun but can also be used as a verb or a modifier, which is the same for 'running' and 'swimming'.
Pitting takes place in a pit, or mosh pit, and involves the actions assosciated with such a place such as moshing or slam dancing etc. Dominantly done at metal or hardcore concerts but has spread to other related genres.
Coined by the addition of the suffix 'ing' and an extra 't' to the word 'pit'.
The word 'it' can be added to form the phrase 'pitting it' which still has the same meaning.
That gig was awesome, I was pitting it all night!
Nah I'm too old for pitting now
Band Member: Good evening (place)! I wanna' see some crazy pitting tonight!
B: Dooood...Im pitting up in this joint..musta had too many corndogs and 40's last night,
A: Damn Simpson, thats some ruthless stuff your letting loose.