As a child, my eldest son hated knowing the proverbial sword of Damocles was hanging over his head. He had a tendency to get into trouble, and he astutely observed that it was better to get the inevitable punishment over with speedily than spend all his time obsessing about when it might be coming.
Or maybe he just took note that, with his father at least, a sin confessed earned a lighter punishment than a sin hidden and untimely revealed by a sibling.
Judgment is inevitable both in this life and the next. Even a family relationship doesn’t earn anyone a pass; in fact, we Christians get ours before the world gets theirs. Peter says, “It begins with us”, and so it does.