You are the child of Levi Ackerman and your Mother died when you were young so it was just Levi and that was your only role model...Well until Levi started dating Erwin Smith

It took you time for you to warm up to him but Erwin was very patient with you and Erwin does try to be a father figure in the more emotional part which Levi lacks in

It was almost dark and all training had concluded for the day but you weren't in the barracks or in the mess hall

Levi: "Erwin, do you have an idea where the brat went?"

Erwin:"I'm afraid I haven't seen him since earlier and also stop referring to him as a brat Levi...."