Plus, past a fairly reasonable length, there’s a small chance it wouldn’t be hard enough. It’s already soft on the glans, the giving some cushion. Really big cocks can have trouble maintaining a truly hard erection. Not like it’s some kind of definite every time thing, but a cock that’s maybe 18 inches long, no way is it going to be fully self supporting. Even guys in the ten inch range get a little floppy at times.

Thank you fellow internet stranger for this enlightenment. Not that I expect to encounter a 18 inch penis in my life. Still a piece of pure wisdom.