an individual who explores the anal passageways of another, through use of a tool such as a dildo or a penis. derived from ass, the anal region of the human body, while spelunking is cave exploring, thus the act of exploring the cavities of ones asshole. also used to describe a homosexual.

When you think up something brilliantly righteous while baked.

1) One who engages in the practice of exploring the anus and rectal passage of another, just as a spelunker enjoys exploring dark, dank, underground passages.
2) A person who acts as though he might enjoy the practice of ass spelunking.

An ass is somebody's bottom or more specifically in this case an anus.
A spelunker is an unexperienced person who has an interest in entering or enters caves.
Therefore, an Ass Spelunker is somebody who has an interest in exploring or does explore the cave-like orifice of an anus.

One man who enjoys hopping and leaping atop another man's ass for long periods of time.

ass fuckers

this word comes from ass meaning butt and spelunker meaning someone who explores caves so ass spelunker means someone who explores the butt hole and its surrounding area