What are the rules for engaging in coitus while living with roommates?

What exactly is the etiquette surrounding this situation? Surely you (and your roommate) are entitled to intercourse in your own home, but it seems disrespectful to do it within earshot of someone who isn’t being invited.

Personally, I think this goes with the territory and is part of the price you pay in exchange for cheap rent, but it is also sort of an uncomfortable situation for all parties…