You don't know what's a word to describe better than 'best' so you add 'iality' from, for instance, specialty, to promote a subject that is considered best than best. In other words it's bestiality.
"Surprise, surprise, I got you a birthday present!" Bill said enthusiastically as Gerald squirms in embarrassment.
"You're the bestiality Bill!"
The tendency to have sex with one's best freinds / freinds, usually due to a craving of intimacy that stems from loneliness. These actions are usually performed whilst in an intoxicated state, and are typically followed by a feelings of regret and shame.
Me: Oh that party was crazy last night!
Freind: Oh really? What happened?
Me: Someone hooked up with two of thier freinds, and they're totally regretting!
Freind: RIP. They crave bestiality.
Me: Facts
The slippery slope fallacy that gay marriage will lead to marriage between humans and animals. Used by rightwing bigots who are frequently self-loathing repressed homosexuals. Notable users of this argument include Senator Rick Santorum and assorted dumbasses at the Drudge Retort.
If you allow gay marriage, the next thing will be marriage between a man and a horse!