After watching the fireworks with everyone, they’d either climb up a roof or walk up a grassy hill, lie down and wait for the smoke to clear out so they could breathe the fresh night air and stargaze until they both fell asleep with content smiles on their lips.
Canon-compliant comment: Stargazing is a surefire way to make Levi loosen up and smile, tested and proven in ACWNR (^_−)☆