I got bored in the shower this week (what are you supposed to do in there anyway?!) and I decided to use my roommate's stray hairs to write the word "MURDER" on the shower wall. I thought it would be funny, but I worried that it might come across as passive aggressive, like I was really upset that she left her hair in the shower.
More than worrying about being perceived as passive aggressive, I suppose I should have considered how creepy that would be. When she saw "MURDER", she took a photo of it to show her coworkers to ask if they thought it indicated some crazy guy had snuck into the house. Nope, just a crazy guy who happens to pay to live there with her.
I assured her that it was a joke and I probably was not actually going to murder her. She seemed to buy it, which might be dumb given that years ago I accidentally threatened her grandmother with a knife.
Today she "retaliated" by rearranging her hair into a tic-tac-toe board. That seems like a much nicer way to communicate with your roommate. I, of course, put my X in the middle square; it may be a gross game of shower hair tic-tac-toe, but I'm playing to win!