Single White Female has met her match.

Most of us move on from the «copying» phase of development by the time we enter kindergarten. It can be frustrating being a 6-year-old whose 4-year-old sister won’t stop doing exactly what you do because she wants to be you so badly. You beg your mom to make her stop copying you, but it doesn’t help. She still claps when you clap, puts a bubble in her mouth when you put a bubble in your mouth, and generally annoys you until you can’t take it anymore. 

Once you grow up, you notice more subtle forms of copying that happen out of habit. One of my best friends adopted «Hey princess!» as a greeting, and now I literally can’t stop saying it. I don’t know if I adopted the phrase because I think it’s funny, I spend so much time with her, so I hear it all the time, or I’m prone to picking up catchphrases, but whatever the case may be, she has no problem with me copying her, as I have no problem with her copying me and my silly slang. It’s not like I’m acting like I coined the phrase first!