In case you were wondering, it was a susurrus
There was an impression he had in her presence. Something he couldn’t quite place. Sometimes it seemed like a quality of the light; sometimes it was almost a sound. Sometimes, she seemed to fill the room.
He took to watching how other people interacted with her, when he could — stall-holders, bus-drivers, children on the street. As far as he could tell nobody else could sense whatever it was.
He had always loved watching her. Loved looking at her. Every inch of her fascinated every inch of him. This puzzle was no exception, and sometimes he wondered whether it wasn’t an excuse he made himself to revel in her all the more.
It wasn’t until the night that she held him as they fell asleep that the mystery was finally solved, and he felt her wings fold around him.