Aroused / surprised expression
  (reacting to situation - not really focusing on viewer)
	(not merely happy or nervous)
	(open eyes helps express things)
	(tongue helps)
	(more intense = better)
	(a sleeping reaction counts)
expression visible  (eye expression is enough)
penetration / impending penetration  (thicker is better)
young character

(the rest of these seem less necessary)

pussy visible  (possible from front or back) (cameltoe / side-folds are enough)
 (position?)  pelvic thrust / back arch
legs spread wide
asymetrical pose / unique pose / angle
depth-aimed penetration  (front or back)  (implied by character's pose)
 (relevent?)  unique situation / reaction