My (half) sister is 12. Her mother has lovely manners etc but has definatley not passed this on to her children.
There have been various things with my half sister to the point where I complained to my dad about the way she talks to adults.
She accidently deleted me off Facebook the other day and hass requested me as a friend again. I don't know why she bothered as thats where a lot of the previous problems came from and I won't talk to her on there anymore. Anyway she sent me a message asking me to accept her, and I jokingly replied that I didn't feel like it (I put lol to make it clear I was joking), she then replied with something else, can't remember exactly what, which I sent another jokey reply. She came back with "why are you being so sad and pathetic?" (not joking) and I said that was not the way to get me to accept her request. She then replied with "sorry brunette, I'm not licking your bum". I got really pissed off then and told her that I wouldn't be spoken to like that, I wasn't accepting her request, end of (as she has a habit of having to have the last word all of the time, which my nan taught me that that is not acceptable).
I hate rudeness like this as I would never dream of saying the stuff she says to me to any other adult now, let alone when I was 12. So AIBU to not want to talk to her?