Royal privates

Some disappoint, so very small;
They are but human after all.
Those on parade, as in the forces,
Are rumoured hung like royal horses.

Female ones are rarely seen,
Particularly, of course, the queen's.
Should you sneak a peak, a waiter
Will pounce, denounce you as a traitor.

Private viewings need consent,
Royal Privates, Royal Assent.
Rest assured, when in the showers
Their naughty bits are much like ours.