Some additional facial animations to express more/different emotions; simple things like tightly squinting the eyes when getting paddled or when she's all the way down deep throat. Of course new sex positions that is inevitable
Maybe a fingering animation... But really the facial animations are what imo add realism to the game.
Speaking of commands I was thinking last night that some voice acting on the girls parts would be nice as far as how they respond, you can express much more emotion through speech which adds even mote immersion.