For the sake of her pride, he won't make any mention of success or happiness when she caves and climbs onto his back. He passes it off as a casual and normal action and stands quickly. It's obvious her weight on his back is of no significance to him in the way he carries himself.

"Now that you have the advantage of height, you may keep watch." There, can't say he doesn't trust you. He glances around cautiously before he begins to stride back from where he came. This would be much easier if he could fly.

"I came across it myself sometime ago. Her name is Lady Elsa, she can bring forth ice from her fingertips and craft it into objects." She even made him a big chair for his big Asgardian butt.