Just watched it On demand..
The title of the episode was "The Lion Sleeps Tonight"

Dex realizes a fellow predator while shopping with the kids.
All said and done Dexter operates in a grey area, subverting the paedos plans as seen on the comp and saving the family unit. The human side he shows is in direct contrast to any and all actions he's displayed. So is his disregard for the "Code". Good show.