During the week, it's easy to identify when your roommate will be out, but on the weekends, he will be impossible to keep track of. This is where your elaborately planned alert system comes in.

Sit down with your roommate and talk about your inalienable right to have casual sex with cute sorority girls. Empower him by declaring that he also has that right, and explain that a few small signals will ensure you both explore this right fully.

Here's what you'll do: You will put a tie/sock/ribbon on the doorknob when you have a lady in your room. That way, your well-intention roomie doesn't barge in whistling an upbeat tune, ready to offer you a beer, while you're making sweet music of your own. It should be noted that this privilege should be used sparingly. Even if you are that good, your roommate should not arrive home to find the signal employed every weekend night for three months in a row. Think of it as a special occasion kind of thing.