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1.
A penis the size of a hugeee gas tank

also called just "GTP"
Joe: H000LY SH111T!!one1!! this porn is like soo good!
Dan: L0L. dat nigga has that GTP. all day, for life.
Desmond: GTP?!?
Dan + Joe: GAS TANK PENIS
by Bethekingdom April 05, 2011