It was the rumbling, his wife gave birth to you but was separated from him and is on bed rest back at the Survey corps- before they could take you back to the Survey corps as a new born baby there were to many titans to take you safely back, Levi held you in his arms with Gabi as they rode on Falco in his titan form, as a new born child, he swore on his life he'd never let anyone hurt you but- his eye's widened when he heard Zeke call out to him

Zeke: Oi Levi! Gabi: gasps No Levi: shit