This term is flexible in that it represents all orifices and organs involved in fucking.
For example, a fuckpipe can be defined as "the pipe which fucks", i.e. the penis.
Alternatively, the fuckpipe can be defined as "the pipe in which fucking occurs", such as the vagina, mouth, or rectum.
That bitch got did in the fuckpipe.
Bill, Ed, and Al put their fuckpipes in each other's fuckpipes.