The bulge that results from wearing very tight pants and placing items (such as cell phones) in the front pockets. Generally received as awkward in females and highly erotic in males.
1. "Yikes! I didn't know Marissa was a guy!"
"No man, that's just her side penis. She forgot to take her wallet out of her pants."
2. Because of Allison's false assumption that Dave had two penises, she invited all of her slutty girlfriends to have sex with him. Little did she know, it was just a side penis.