Similar to a birthday, except instead of celebrating the day a man was born, he celebrates the day in which his penis reached its maximum girth.
Hey ladies!! Today is my girthday, and i was hoping you'd celebrate with me by letting me go deep inside! Whaddaya say?
by MikeyB1980 January 16, 2014
Girth Day occurs every May 1. It is a day to honor those among us that are Girthier than the average man. Examples of honorees include: Arnold Schwarzenegger, Jean Baptista, and Ron Jeremy.
Happy Girth Day!
by jmn3813 April 30, 2011