From TV channel disputes to arguments over unclean dishes - moving in with strangers can be an uncomfortable experience.
But as one woman discovered, there are far worse things that can happen when sharing your space with people you don't know.
The woman, who gave her name only as Sarah, told 9 Honey how she caught her male housemate rubbing his genitals on her toothbrush after becoming suspicious that somebody was going into her room.
Sarah, 28, said her horrifying experience started after she and her boyfriend found another couple looking to house-share on Trade Me.
After a few months living together, she began noticing that things were moving around and suspected the female housemate was coming in to use her beauty products.
"When you find your flatmates blonde hair in your underwear drawer... you've got to ask yourself questions," she said.
"I often used dry shampoo, which was brown to match my dark hair and she has blonde hair. One day after work, I asked if she had dyed her roots because they were so brown and she went bright red. At the time, I didn't understand why a simple question would get that reaction, a couple of weeks later, I found out why."
Sarah and her boyfriend began putting a shoe behind the door, knowing it would move it the door was opened.
Sure enough, every day the shoe moved from its spot.
Determined to catch the make-up thief, Sarah then bought a webcam and set it up in the corner.
At first, the camera caught exactly what Sarah intended it to - her female roommate coming into her room and using her things.
But what it captured next that will haunt everyone that watches the footage.
Her male housemate can be seen coming into her room, going into her bathroom, and pulling his trousers down in the corner.
The man then stands there for around 20 seconds without moving, before his hand reaches out and takes a toothbrush from above the sink.
He then moves it over toward his crotch and out of shot, before replacing it moments later and walking out.
Sarah said: "I initially didn't believe my boyfriend when he called me and told me ... why would someone do that? We hadn't done anything wrong...I cried!"
After confronting the man about the footage, she said he admitted to having "a toothbrush obsession" before going bright red.
Sarah added: "I said we had a video of the whole thing and we knew his girlfriend was using our stuff
"I said we were going to the police, moving out, and telling the landlord."
She said they moved out a day later, having bought new toothbrushes, but did not mention if the landlord or police decided to take any action.