A room or place where you take a date or hook up that is designed to create an atmosphere or mood based on your sexual preferences and desires. For example, if you are into BDSM, it could include a bed with a bed post equipped with different types of restraints, dark leather furniture, and a dresser full of toys. If you are trying to create a romantic setting, it can include a bathroom equipped with a large tub full of bath products and candles with a sensual low lit warm bedroom environment.
Dude, I met a girl at the bar last night, and I took her to the closing den. Once she walked in it was a sure thing.