don't forget to water your plants

Hi reddit. A few days ago I (NB27) was getting ready for work when I caught my roommate (NB27) in the bathroom brushing their teeth with my toothbrush. I got really mad at them for this, but they didn't think it was a big deal and said I was overreacting.

Their logic was that because they were my exact duplicate all our germs are basically the same anyway so it's basically like just one person brushing their teeth twice. But my opinion was that we became "different people" one year ago, when they woke up in my bed beside me one morning without any explanation. But this made them mad because they said from their perspective I was the one who woke up in their bed one morning without any explanation, and they accused me of claiming to be the original again. Things got really heated after this but neither of us was able to kill the other because our abilities were perfectly matched so we basically just declared stalemate like usual.

This whole ordeal had been especially disconcerting to me because up until this point there have been no real points of divergence in our personalities. Every time we have made a decision we would both make the same choice, all of our opinions and beliefs have been identical, and any time we converse it's difficult because we keep trying to say the same thing at the same time. So for us to disagree on anything is unexpected let alone something this big. I was hoping to use this as a clue to help prove I was the original but unfortunately none of my friends or family can remember my stance on toothbrush clone sharing so I was out of luck there.

Anyway they still keep using my toothbrush even though there's another one there because they "like the blue one more than the purple one" but the blue one is mine!!! I really don't think its unreasonable to ask them to use a different toothbrush here, especially since I was here first. AITA?

EDIT: mods this thread isn't a duplicate, they just posted the same topic from their perspective at the exact same time that i posted mine. stop flagging this for deletion.