It's when you're mom gets boned some awesomeley with pies and tacos so explodes.
Billy: Hey Tom did you hear what I did last night?
Tom: What did you do?
Billy: I did Super mega awesome to the power of pie divided by taco with a cherry on top with your mom with your mom.
Megatron shagging a labrador is a old saying created by the most intellectual people of the ancient internet. Oxford University have made many studies on this phenomenon, and have failed many times. The true meaning of this great example of history is still a mystery.