Ingredients: Chopped Nuts and/or Hundreds of Thousands and/or Chocolate Chips
After ejecting one's man load on to the face of your victim you follow up by throwing one's desired topping(s) on to the now load laden face thus causing it to stick, creating the sneaky sundae.
Bonus points are awarded for throwing a cherry in the mouth to finish.
She always complains I never cook for valentines day, so this year I'm going to make her a sneaky sundae.
Someone who schemes. One who has a shifty, guilty, and/or mischievous air about them. A sneaky dickens is a crafty trickster. Whether they get away with their stealing/pranking/schemes or not, they are deemed a sneaky dickens for life.
Sarah: Look, Chantal stole Carly's french fries when she wasn't looking!