Thor shifted with Diana to make her more comfortable as they stretched out. With the couches in mind, they'd taken one of those so they would have room. Eventually, his arm curled around her, hand resting on her arm. He rubbed at it lazily once as they settled, eyes on the movie for the most part, but every so often, the light reflected off her eyes and made them sparkle. He lost track of the movie at those times, eyes drifting to Diana momentarily.
This was a small moment, in the grand scheme, but to Thor, it was everything that night.