Bibro
As opposed to fans who are particularly attached to one brother or the other, some fans identify as "Bibro", indicating that they are equally devoted to both brothers. It arose in the early seasons of Supernatural when there was particular animosity between some Dean Girls and Sam Girls, by fans who wanted to be clear they had equal affection for both brothers.
More recently the term is used pejoratively by some fans of Destiel to refer to fans who favor the Winchesters, to the exclusion of Castiel, although the term used for those fans is more generally Bronlies.
