That's because sisters will steal your $hit and use it without a second thought; I'm assuming that you were an only child.
Neither do I; then again, most of my friends are dudes and don't care for makeup or fruity-smelling shampoos.
If you had a sister, half your makeup would go missing within the first 24 hrs! Extreme indeed!
That's true but then I would make my parents buy her the same stuff so that she doesn't steal mine. It would be annoying if my stuff went missing. Telling them about what products you use is different. I wouldn't mind letting her know what I use as long as she bought her own stuff. There shouldn't be competition between sisters.