Happenis (pronounced Happiness) is the erection of a penis. Men are typically not held accountable for their actions as this condition usually leads them into relationships that otherwise they would avoid.
by Sex and the Sunday Morning Woody July 08, 2006
by CelticsFan69 August 14, 2008
When you have a very happy penis.
by Verlaine Stain June 27, 2014
As Justin slept after a solid rogering, Shaun placed his flaccid penis on Justin's mouth and made the shape of a smile. He took a photo of this to show Justin the HapPenis when we awoke.
by Antrobus June 03, 2016