You live in a dorm. With a roommate. And, short of pitching a tent over your side of the room, there's very little chance at privacy. So, someone made the Privacy Pop, a real tent that's designed to sit right on your bed.
Granted, you can buy one of those lavish beds with canopy tents like rich people do on TV. Buy you're neither rich nor on TV. Plus, you already have a bed frame and a mattress, so a tent that can integrate into them should play more into your existing privacy needs and budgetary constraints.
The Privacy Pop is a tent that sits right on the bed frame, with your mattress laying snugly on its floor. It comes in just one size that fits both twin and twin XL mattresses. When pitched, it can be fully zippered on all four sides to give yourself a walled-up box for ultimate privacy. It won't block sounds, though, so keep the noise down with whatever you plan to do in there (or wear earplugs if the action is going on outside).
For those times you don't need the privacy, you can open large windows on any of the sides (just unzip and fold up), so you don't have to take it down. When removed from the bed, you can fold down the unit into a portable bundle just like any regular tent.
While this will be great for dorms, the Privacy Pop will likely be even better for kids' rooms. I mean, it's like getting a fort right in your own bed. It's available now, priced at $199.95.