The act of double chipping is similar to that of double dipping: When one takes two chips instead of just one and inserts them into the dip, effectively getting more dip out of that scoop. Often followed by receiving the stink eye from those who you are sharing the dip with.
Bro #!: Guy, you're such a double chipper, it's ridiculous. Look, we're already out of dip!
Bro #2: I'm sure your double dipping isn't helping all too much either, numbnuts.