Beside the bathroom sink, precisely parallel with the edge, lay a plain blue toothbrush. She poked her head out into the attached bedroom. No clues for her there. Her hosts had said that no one else used this bathroom. Did they expect her to use this toothbrush? Without touching it, she examined the toothbrush. There was no wear on the handle that she could see, the brand name still standing out proud and sharp. Bending down close, she thought she saw the bristles splitting a bit at the ends. By manufacturer's design, or a sign of use?
She checked the trash can under the sink, but didn't find the plastic packaging of a toothbrush fresh from its wrapping. Had they opened it, then taken out the trash? Unknowable.
Would her hosts be insulted if she didn't use the toothbrush? Would they know? Maybe that's why it was so precisely placed. She bent close again, looking for a single hair laid on it to reveal that she'd touched it. Or maybe it was a test. If she used it, they'd be disgusted and never invite her back.
She brushed with the toothbrush she'd brought, thinking about how she overthinks these things.