A phrase short for "what the hell?" used to express ones feeling of awkwardness or astonishment toward something someone else said. Similar to "the fuck?" but used when one is feels less astonished or awked out.
Car full of guys on there way to pick up a girl.
Bobby: "Hey you guys want to like take our pants off so when Lauren gets in the car, it will take her a second to realize were kinda naked, it'll be hilarious"