I like to imagine that Levi became super clingy to Erwin for a while after he Ackerbonded with him, and obviously Erwin would have no idea what was going on.
They get back to base and Levi never leaves a horses distance from Erwin. Erwin is cautious and keeps glancing back, expecting Levi to attack him. Then when they make it to Erwin office, Erwin’s surprised as Levi follows him in. Erwin braces himself ready for an attack only to turn around as see Levi’s power cleaning his office because it’s ‘too filthy’. Levi starts bringing Erwin his meals when he’s to busy to remember to eat, and Erwin eyes it wondering if it’s poison. Every few hours Levi would silently change the bandages on Erwin’s hand with a somber look on his face. When Erwin stays up late working at his desk, Levi nearly headbutts him declaring that he needs to rest. Erwin learns that Levi doesn’t sleep much when he wakes up to find Levi standing guard on his room. Every time Erwin heads outside Levi’s throws a cloak around him saying “you need to keep warm.” Levi helps Erwin with paperwork, laundry, training, and whatever else he sees Erwin needs.
One day, Mike passes Levi jogging out of Erwin’s office with a determined look on his face and a pile of laundry in his arms. Mike makes his way into the room to find Erwin, hands folded on his desk, as he stares after Levi. Mike shuts the door behind him, but Erwin’s gaze is still fixed in the same position. Mike glances around the office which was cleaner than he’d ever seen it. Taking in a light sniff there was a faint smell of cleaning products, but it was mostly overshadowed by the steaming tray of food sitting on the edge of Erwin’s desk.
Mike narrowed his eyes. “Okay, what happened?”
“I really don’t know.”
Erwin is staring beyond the barrier of the door trying to internally solve some strange puzzle, and Mike doesn’t think he’s seen Erwin blink since he came in.