Levi, your Corporal. Couldn't stand seeing you hurt whether physically or emotionally he wouldn't have it. It was better for him if you were in the military, he could keep close tabs on you.

Though, he's gone to certain lengths as to keep you safe. Hes even gone to the extent of chaining you up, only to let you go for the upcoming mission.

Even if it calls for it he'll lock you up in his office just so you won't be around the filthy soldiers of the Survey Corps.