Sharing. We were all taught from a young age to share our stuff by (surprise, surprise!) adults.
I'm gonna stop the rant here, if you want to read it, look at my other book, "Randomest Things In The World", you'll find it there when I publish it.
Point is, share stuff. It doesn't have to be your phone or computer, just the smallest things, like an earbud or a book- wait, no, NOT a book- a sweater, some chips. That would be enough. Again, bonding! If they see you trust them with your stuff, they'll respect your stuff more (probably because they know if they fuck your stuff, no more using your stuff).
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How To Survive Your Younger Sibling
Random17 tips to surviving life with a little dem- I mean sibling that will probably save you from strict parents and (sometimes unfair) punishments