The psychological disorder when two friends hang out so much that their friendship borders on codependency, and they only act out when around each other. This results in dick riding that is usually harmless but can turn into chronic douchebaggery if undiagnosed.
Me: those guys are really cool, but not when they act like batman and robin. Its unhealthy.

Jesh: yeah dude, they are totally goat and oyster.
by Thedudelebowski August 8, 2013
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