What is Butt Beer?
1.
The beer funneled out of someone's asshole
"you kids with your elephant walks, circle jerks, and drinking butt beer"
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2.
Beer filtered through the ass crack.
"My butt beer tastes like ass!"
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3.
Beer filtered through the ass crack. (Hairier the better of course.)
The frat always chose to filter butt beer for the pledges through Pat's unusually hairy ass crack.
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