Get a plain white sheet (of reasonable count and thickness) or a throw to use as a barrier between the items and the surface underneath. Can drape on top of bed (on top of covers, I would hope), floor, table, etc. Also, buy a small reflector to increase the effectiveness of window light, or use one of those car windshield reflectors which are cheaper and work as well.
Sure, when it comes time to copulate, everyone remembers the hole and the sheet, but don't forget this part, equally important, lest you ache to stir the sky, in all its fiery condemnation:
The times for conjugal duty prescribed in the Torah are: for men of independence, every day; for laborers, twice a week; for ass-drivers, once a week; for camel-drivers, once in thirty days; for sailors, once in six months. These are the rulings of Rabbi Eliezer.