Coppermane admires his princess in every conceivable way. Fluttershy has told him stories about how she and her friends defeated Sirens and other evil entities. She possesses magic, transforming when she plays her tambourine. She's amazing with animals, seemingly able to speak their language.
Fluttershy is an amazing girl, and Coppermane is humbled to have her all to himself, but when he thinks about her accomplishments, he can't help but feel insecure about his own feats, or lack thereof.
He decides to have a little talk with his princess, and ask why she settled for someone so clearly inferior to her.
Coppermane & Fluttershy Series: 3.1