When you use an iPhone's Siri function to bypass security and send shady text messages to contacts in the victim's phone. This is done buy holding down the home button, then saying "text Mum that I like butt stuff".
Neil: "Hey I sirijacked you to sext your wife" Me (checking texts): "That's my sister you ass! You will pay for this sirijacking!"
by Barabbit Obama December 07, 2015