Jubal sighed. "And I could sit here all day explaining it and you still wouldn't understand it.  My dear, there are aspects of sex on which it is impossible to communicate between the two sexes of our race.  They are sometimes grokked by intuition across the gulf that separates us, by a few exceptionally gifted individuals.  But words are useless, so I won't try.  Just take my word for it:  Duke is a perfect knight, sans peur et sans reproche - and he would like to have that picture."