There are four requirements to trigger that scene. You need to have seen the post spanking spying scenes for Amy, Cassandra and Rachel (spank them in your office then spy on their rooms). Plus you need to have resolved Maxine's weekend protest. The naked studying scene is a lower priority, so it's shouldn't interfere. If you truly stuck then we can probably fix your save with console commands, but you'll need to ask in the help channel on our discord.