"Don't get me wrong, Dean is actually a good bloke, but he's the exact opposite of compatible with Hermione. Their discussions do not take place at eye level. He lacks the calm needed to deal with her temper, as well as the authority to put her in her place when she goes too far. You, on the other hand, possess both of these qualities. Plus, you respect her boundaries, which Dean never did. Hermione isn't easy, but there's a lid for every cauldron and that's just not Dean."