system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Yes, a question about the penis.

I'm not sure how to word this question, but I try my best.

Guy A has a 2 inch penis when flaccid. Guy B has a 6 inch penis when flaccid. When Guy A is aroused, his penis grows to 6 inches. When Guy B is aroused, it basically stay the same size but only gets hard.

What is happening with Guy A's penis? Like.. Where does Guy A's length go when he is soft? Sorry if the question was unclear.. Just was curious and having a hard time explaining in words what I am trying to ask. lol    

Edit: Umm.. I didn't expect this question to be so popular.
gpt
Think of it like the difference between a beach ball and a balloon, both the same size when filled with air. You deflate the balloon and it fits in your pocket, but the beach ball will still be big.

It's about elasticity and how much spongy erectile tissue there is, which varies across people. The spongy tissue has lots of space to fill with blood and expand/contract in size, and the higher the ratio of this tissue to other types, the more you're a grower rather than a show-er.