I gave my mum my iPhone 4S on iOS7. Thought i'd signed out of everything but iMessage still had my Apple ID listed. I received today an iMessage from my aunt (who never texts me). Very strange. I tell my mum & she said that she actually sent that to my aunt, not me. WTF? So we look at her phone, i sign out of iMessage & anything else i can find & sign in as her with her Apple ID. Tonight i get another iMessage from my aunt which is actually a text message my mum sent my aunt. Why is this happening & how can i stop it?