Do hotels change their sheets between guests? Investigation reveals disgusting truth

You look at those white sheets and fluffy pillows in a hotel room, but have they already been slept on?

An exclusive investigation by Inside Edition found out the disgusting truth about hotels -- some did not change bed sheets between guests.

At a Residence Inn by Marriott in New York City, they used a harmless washable fluorescent paint to spray "I slept here" on the bottom sheet of the bed.

The paint is not visible to the naked eye. It can only be seen when a UV light is shined.

Read also: Life-changing insider secrets that big hotel chains don't want you to know

The next day, they checked into the same room under a different name and found... the paint was still there.

"This is absolutely disgusting," said the journalist. Ann Mercogliano.

She questioned the manager, "Why weren't those sheets changed?" 

"We make it a custom to change every checked out room sheet," she responded. "However I do not know what happened in this situation."

The Marriott Corporation apologized and said it takes these issues very seriously. They are now inspecting the room to ensure this does not occur again, they said.

You might want to bring your own sheets next time you stay at a hotel.

Inside Edition is also checking in to nine other hotels to find out if they change their sheets.