A vaguely-related out-take from "...as we join this man and this woman..."
After the fall of Voldemort, the remaining members of the Order of the Phoenix met one final time at Number 12, Grimmauld Place, during which meeting the newly-appointed Hogwarts headmistress carefully suggested to Snape that perhaps he might like to find something to do with himself rather than teach now that his time as a spy had come to an end.
Snape thanked Minerva for her offer, but replied that he found himself unwilling to forgo some of the pleasures to which he'd grown accustomed.
Alastor Moody scowled.
"Don't want to give up the thrill of having small children cowering in fear as you pass?"
Snape sneered at Moody, and without a word of farewell to anyone in the room, Apparated back to Hogwarts.
He had not, it was noted later, disagreed with Moody's assessment of his motives.
The worst thing about tyranny - whether the great tyrannies of would-be dictators or the small, everyday tyrannies of schoolteachers - isn't its ugliness, but rather how very attractive it can be.