Heart with slot on one side - Voronoi Style

This makes a great Valentines gift.
There are three different variations of this heart: A, B and C.

This Heart has a slot on one side to put something into it: Maybe a little paper with a message to your loved one.

http://youtu.be/83wFYNWB1AI

The Heart without slot can be found here:
http://www.thingiverse.com/thing:246864