f.i.e.t.t.s.
F. I. E. T. T. S. is the only thing that keeps your brothers from turning you into the school principal for skipping class.
My brother skipped class. I said, 'F. I. E. T. T. S. or I'll tell the principal.'
I skipped class. My brother said, 'F. I. E. T. T. S. or I'll report you.'
When my brother tried to rat me out, I said, 'F. I. E. T. T. S. or you're dead.'