You're probably being too nice, actually.
There are a few responses that unlock his preview at the end.
Personality choices: be adventurous ("some excitement","trying to escape"), be mean (refuse to talk to Camilla at tea, say you "don't want to be bogged down" by Myrrine, lure a girl into the trap), and be power-hungry ("knowledge is power", "take over the world", "the god of weapons and warcraft"). You only have to pick three of these choices to qualify, but maybe try more to be safe.
Also you must be nice to animals: choose "pet the dog" or "I thought it wasn't fair" at the arena. Definitely don't avoid the dog.
Augustus isn't like most of the other love interests. He's there primarily for people that like to play evil.