How could he not be happy right now? There's millions (billions?) of fireflies, a beach, the weather is neither too warm nor too cool, and he's made a new friend.

Erwin hadn't meant to fluster him, but it is kind of cute the little flush that comes over Levi's face. He doesn't say it, though, but holds the jar steady for Levi to deposit the little creature inside, and then carefully puts the lid back on. It's got holes in it, enough to ensure airflow but not so that anyone can escape.

"Leave...?" What did he mean by that? The sound is there, sorta, but...Erwin tilts his head.

"I think it's nice to say. How do you spell it?"