Two characters in the comic Life in Hell
by Matt Groening
. They are dressed identically, in vaguely Charlie Brown
-like clothes and fez
Originally their relationship was rather ambiguous; when asked if they were lovers or brothers, Groening replied, "whatever offends you the most." However, for several years they've been obviously out.
They are still ambiguous about each other, though, and specialize in jokes about passive-aggressive behavior and "family values." They are the protagonists of the funniest cartoon ever.