While Lupin holds the Defense position, Snape’s overtime duties are downgraded from de facto Defense teacher and Auror to support staff: Lupin’s on-call substitute and his private apothecary, since few other than Snape have the talent to brew Wolfsbane, the potion that allows werewolves to keep their human minds when transformed.
Another time Dumbledore pressures Snape to console one of his childhood abusers without a word of protest.
