Am I the only man who thinks that, even aside from questions of decency or fashion, those penis pants would be horribly uncomfortable? You can’t make something properly form-fitted to a body part that routinely changes its shape and size.
That’s why it should be illegal to change shape and size.
Codpieces used to be a thing in the Middle Ages. Ian Anderson of Jethro Tull used to sport one, but as a modern fashion choice, it hasn’t caught on.