In the heat of the moment, Erwin is and has been giving mixed signals this whole time. He'll realise that later on, when cooler heads prevail, and make a quiet vow to be more direct in the future. It's so rare for he and Levi to be out of step with each other that when it does happen, it takes him by surprise.

Erwin leans his hips back when he feels Levi move his hand between them, and he groans against Levi's lips when he first touches him and then pops the button of his fly. His cock pushes out of the gap in his pants, aided by both gravity and Erwin pushing his hips forward, and he shoves it into Levi's hand. They're only separated by the thin fabric layer of Erwin's underwear now, and Erwin drops his head down to rest on the pillow next to Levi's ear. He's panting through his mouth, his entire body trembling and keyed up, and his hand clenches into a fist against the mattress.

"Levi, please..."