Faux homo- or bisexuality between two (usually male, but see t.A.T.u. for the contrasting example) members of a band, expressed via acts of fanservice. See also Panic! at the Disco, Tommy Joe Ratliff and Adam Lambert during the latter's Glam Nation tour, My Chemical Romance, Katy Perry's I Kissed a Girl, etc.
Gerard Way says he's pulling out the stage gay to challenge people's homophobia, but I think he just likes to make teenage girls scream.