Toofers (var. Two-Fers) are an insular subculture in American Culture, and later subspecies and culture group in its own right.
Names
Toofer is a contraction of "Two-For-One," a popular catchphrase from the smash hit sitcom Fat Fuck in a Big Fuckin' Truck.
Pejoratively, Toofers are often called "Bogos," from another character in the same show. This is meant to be criticism, I think?
Customs
Co-Shitting