Oklahoma pile driver
The act of plowing your whole fist in your sexual partners anal cavity/vagina hole. This is a stimulant in order to make an orgasm of any sort feel better after the act of love-making.
Guy 1: dude I just had sex it was great for us both!!
Guy2: did you use the Oklahoma pile driver?!?
Guy 1: yea I did it worked so well!

Guy 2: well that explains why she liked it so much.