flat cocking 

The act of two women (lesbian or not) sitting across from each other with their legs spread open and sideways, allowing for full contact of their vagina to one another. Once in contact, they begin rubbing/grinding themselves against the other's vagina. Not entirely unlike the act of using a two-headed dildo and coming all the way together, only this does not involve a dildo.

My dyke neighbors would probably spend a romantic evening flat cocking each other, since they were too poor to buy a dildo or strap-on.

I can't believe nobody has heard of the term "flat cocking"

flat cocking by RDSTUD September 21, 2007

flatcocking 

(noun) Slang term used to describe lesbian sex.

Shitpants and her friend there have been flatcocking for so long, they are starting to look alike.

flatcocking by Dave Brorsen February 23, 2006

Fatcocking it

A different way of saying “big dicking it”

I was fatcocking it on the way home from work today

Fatcocking it by Mr insomnia May 7, 2023