WARNING: There is NSFW material (including pictures) in this post. Please view with discretion.

Snakes and lizards have what is called hemipenes, which is essentially a two-headed penis. Two penises on one organism might sound pretty wild, but did you know it can occur on humans as well? About 1 in 5.5 million American men will be affected by a condition known as diphallia, resulting in two penises.Though diphallia is fairly rare on its own, actually finding someone who has the condition is made even more difficult by the fact that it usually accompanies highly deleterious congenital conditions, such as other duplicated organs or spina bifida. When the condition is severe, these defects are insurmountable.

The condition isn’t genetic, but could be caused by irregular homeobox gene expression during the 4th week of fetal development. This change in expression is brought upon by mutations in the genes or environmental factors.

The degree of the penises’ functionality is entirely dependent on the individual. Some have two penises that are of normal shape, size, and function, while others can have genitalia that is small, malformed, and unable to urinate or ejaculate.

One man who has two fully-functional penises goes by DiphallicDude (or DoubleDickDude, which morphed into DDD), as he is committed to keeping his real identity private. He is an American man in his mid-20s, living out on the East Coast. Beyond that, not much is known about who he really is.

About a year ago, he did an AMA on Reddit, that turned out to be one of the most popular of all time. He even submitted pictures as proof (obviously NSFW), if you’d like to see what diphallia actually looks like. When he said “Ask Me Anything,” Redditors did not hold back, dying to know what it is like living with that condition. It was revealed that DiphallicDude is bisexual, and has had sex with over 1000 people. While he didn’t go into too explicit of detail about his sexual experiences, he was able to confirm or deny most of the questions he was asked about the mechanics of everything.

His book, Double Header: My Life with Two Penises, was released on Christmas Day. It has been holding the title of #1 Bestseller for Kindle in 3 different categories. Upon the book’s release, he has done a series of interviews for radio and web. All of the sexy details left out of the AMA have been described in the book, in addition to all of the other ways diphallia has affected his life.

Recently, he gave an interview with BBC Newsbeat, discussing what it was like growing up. His parents cautioned him to keep his condition private and not tell other children. He said that he first thought to keep the secret so he didn’t make other boys feel bad for only having one, and it wasn’t until he was a teenager that he realized that he might have been the one getting ridiculed for being different. When he was in high school, he actually considered having one of the penises removed. He ultimately decided against surgery when he realized that it was something he always had, and it didn’t bother him.