More commonly known as spending the night, a camp out is when a guy has one or more of his friends... well, spend the night at his house. This is not to be confused with a slumber party or a sleepover. Slumber parties are for girls. Sleepovers are for kids under 9. Despite what the name implies, usually no camping outdoors is involved, although sleeping bags will probably be brought over. And a few tents might be pitched *badum-tish*.
"Dad, can I have a camp out with a couple of my friends tonight?"
"In the backyard, son? Why sure, I'll just go to the surplus store and get a couple of canteens, a tent, some MREs..."
"No, I don't mean outside. We'll just be playing MW2."