Yet another term for the male reproductive system.
Used on social media because mfs think that saying "penis" seems kinda odd but saying "pp" makes it funny. If yo mom peeks over your shoulder while texting you'll be safe because you used the term "pp" instead of "penis". On the contrary if she knows what that means you're fucked and not in the fun way ;)
Another way to say penis, usually referring to the fact that your dick is small. Saying pp is usually said by a younger audience, they think its funny.