Also known as the BGS, this is a loving sexual act in which the giver urinates up the butt of the recipient.

BGS tournaments are also known to occur in some parts of the United States, though the rules of the tournament aren't well known.
I couldn't believe the sensation brought on to me after receiving my first BGS.

After years of BGSing, I have a permanent limp.
by Dave February 12, 2004
Get the Butt Geiser Surpriser mug.