extratesticle 

NOUN : A male with 3 testicles instead of 2.

NOUN (2) : The third testicle in such a position.

NOUN (3) : Slang for extraterrestrial.

Extratesticles are normal people like you and I. You would never know someone was an extratesticle if you saw them walking down the street.

extratesticle by Echoside March 31, 2005

Extratesticular Activity 

One who excessively Maturbates after work or school or is Gay and enjoys playings with other mens testicles.

My friend Frank engages in many "estratesticular" activities with his Flomo friend Leeroy.

Extratesticular Activity by Richie Rich April 4, 2003