Gaybian
Gaybian (pronounced "gay-bee-an") is a CWC-ism for a male lesbian that has sexual feelings for women, devised by Chris in February 2009. It was introduced in the Clyde Cash blackmail YouTube videos, containing his confessions of being homosexual (the video Captain's Log, Stardate February 5th, 2009).
Gaybianism
It transpires that this was Chris's get-out clause of confessing that he was gay, in a "fingers crossed behind his back" way. As Chris used to believe that lesbianism is perfectly fine and natural, while showing disgust for male homosexuality, this is Chris's way of justifying homosexuality. This is probably because on an episode of Family Guy, when asked about homosexuality being a choice, a lesbian Meg knew said nonchalantly "well, not for guys" (which was the whole joke of the episode, not that Chris notices). This would explain why when confronted with a lesbian fan, he'll say that he's "disappointed."
The whole "male lesbian" thing may be stolen from British comedian and transvestite Eddie Izzard. If so, Chris probably does not realize that Izzard is a comedian, and that it was a joke.