What do you do when your child does something so irrevocably NAUGHTY. and I mean unforgivable at any time in the present and will take quite some time to get over?? (even though all our children are angels and I bet only mine would EVER had done something so terrible in my eyes!!)

I have locked them out the back (and no I'm not divulging the WHAT) and need to know what do you do for the "Major bads"??