furtive

       furtive (adj.) – secretive; sly

for your edification:  The fantastic word furtive, by definition, means secretive or sly. As I am sure you have already astutely noticed, the beginning of the word furtive is “fur.”  You know a tremendous way to be amazingly secretive or sly and no one will be at all the wiser?  With fur.  As in, body fur.  “What’s that?” you say.  “Why, if I grow a beard on my countenance, then surely that is not a secret.  If I have the furriest armhair this side of the Mississippi, why, I could not find a way sly enough to prevent it from peeking out of my shirt sleeves.”  Oh, You.  Sweet, innocent, You.  I’m not talking about your face fur, or your arm fur, or your nipple fur.  I’m talking about your fur down there.  You know:  South of the Mason Dixon.  You can do whatever you want with it!  That fur is your furtive super-sly little secret.  It could be a jungle down there.  It could be llama-shaped.  It could be green.  It’s up to you!  And, shazam, it’s your little secret.  Congratulations, you sly dog, you. 

examplification -  Gary:  How was your date with Tiny Tina?

Carl:  It did not turn out as expected.  She is a furtive one.

Gary:  Dude.  I don’t speak German.  What do you mean?

Carl:  It seems Tiny Tina is hiding a not-so-tiny secret.  She’s like a fur-factory down there.  Like, a family of four could keep warm in winter hiding in that fur.  It’s Furtown, USA.  Fur score, and furty years ago, no one taught her about trimming her fur. 

Gary:  A furry furnace, huh?  I can dig it.