Like fucking... but way harder.
After getting your mom drunk, we went up to her and your father's bedroom and started fucing with such passion that I broke her legs and back.
Like fucking, only better. Usually used in chat rooms, by people who are too cool to use the 'k' button.
Jules: I wanna go to the mall, and watch a goddamn movie.
Jojo: Let's fucing do it, dude!
Dick: That's fucing awesome.
Jane: I know, I know.