Because I have absolutely fucking had it with the squabbling over the computer. And and and - this is between DS2 and DD who is 21. Yes, twenty-fucking-one. An adult. She can vote, work, and marry but she can't negotiate in a reasoned manner with a 12 year old.
I have just screamed at them with the discs in one hand and the secateurs (which I can't even bloody spell) in the other. Next time - the discs die.