The physical process of reversingcourse as one moves their head from a woman's breast towards her genitalia.
"Karen begged me to go down on her while I was suckin' her titties. It sounded like a good idea, but when I got to the vicinity of her navel her pussy stench overpowered me and I had to embark on a northbound migration. Ewww! Stank city!"
Further describing the position of the males while performing the #brooklynbridge on a female parter. Northbound lane would be plowing the female while the Southbound lane will be getting felatio from the very same woman.
