You should not be naked or have intercourse in a room with holy books, unless:

1. There is a wall or divider between yourself and the holy books within 10.5 inches of the ground and at least 40 inches tall (or as tall as needed to block a line of sight between yourself and the book), or
2. You cover the books with two layers of paper or some other material.

Reason It is not proper respect to the holy books.
Note This is true even if the couple is covered, as is the proper practice, and even if they are more than 4 amot/7 feet away, since the entire room is considered to be one domain.