A pig roast is preformed when a female engages intercourse with two males, one initiates doggy style, while the other recieves head. The result should look like a pig being roasted over a fire.
Guy #1 let's fuck Julia tonight!
Guy #2 ok! But I get to go first!
Guy #1 don't worry about it! We can go at the same time! You get the back and I'll get the mouth!
Julia: like a pig roast! I'm excited! Let's do it!