His big liquid brown eyes.
The fact he sticks his nose out of the stable for a kiss when I'm leaving.
When he begs for food by flapping his leg.
The soft bit at the side of his muzzle, between his lip and his nostril.
He has the most expressive face I've ever seen on a horse.
That he knows when I'm not feeling great.
His Roger Moore eyebrows.
His shoulder is just the right height to rest my head on.