Someone who is both a gay man and a lesbian! Yes this is a valid identity, there could be many reasons someone identifies as this, one of which is mentioned below
Person 1: Hey you know how I'm genderfluid and my sexuality changes depending on my gender (a form of abrosexual)
Person 2: Yeah?
Person 1: Well, I've realized that whenever I'm a man I only feel attraction to men and never women, but when I'm a woman I only feel attraction to women and never men, making me gay when I'm a man but lesbian when I'm a woman. So! I decided to use the label gaybian to explain my experience :)
Person 2: Woah that's so cool!
The gayest entity in the entire Milky Way, if not universe. It has no gender and can only be referred towards one person by the name of Sebastian Ng. He is your typical tryhard and is a warty,loathsome, vile creature to our planet. If you see a Gaybastian be sure to wear an N95 mask to prevent internal tryhard infection. Pre-warning : They reek.