And now for something completely disgusting for you to carry with you into the weekend.
Reporters from Inside Edition undertook an experiment recently at nine hotels to test whether sheets were being washed between guests.
At each property, they sprayed bed sheets with a harmless invisible paint that can only be seen under a black light. Then they checked back in the next day under a different name and scanned the sheets to see if the paint was still there.
In three cases it was, including at the Marriott-branded Residence Inn in New York City you'll see in the below clip.
Watch it and feel your skin crawl.