Sokka was getting mildly sick of Toph's complaints about how much she hated flying. So she couldn't see. Big deal! Sokka couldn't earthbend, and he wasn't complaining!
Leaving Katara to comfort the other girl, Sokka climbed over the saddle to join Aang on Appa's head.
Aang turned toward him, greeting him briefly. Then they sat in silence for a few moments.
"It's weird, having another person, isn't it?" ventured Sokka after a while.
Aang nodded quietly. "Yeah." After a pause, he grinned. "But you two will always be the first."
Sokka smiled, feeling warmth suffuse him from head to toe.