Things that a teenager might ask, and a serious answer:

Q: “What is a penis like?”

A: When metal is really hot it becomes malleable, but when a guy gets more and more hot it’s the opposite.
It’s more like a sponge but on the inside. When normal they’re small but it expands as it soaks up water. In this case it expands to it’s capacity and holds the pressure. If you press on it like a balloon it pinches the pressure to the rest of itself and it slowly loses it over time unless there’s more circulation.