The talk with Lucy might not have given him a direct answer. But it had pointed Tristan in the right direction.
So far, his attempts at showing Ariel that he had deeper feelings for her, had revolved around doing the expected things.
Gifts and compliments.
Now Tristan realised that his approach had been all wrong. Ariel was his wife, not somebody that he was looking to close a business deal with. And given that he had just discovered her character as a truly selfless person, she would not be moved by expensive gifts and smooth words. She was somebody who needed honesty from him.
He had to make sure that whatever gift he gave Ariel, it came from the heart in order for it to move her. But so far, knowing that, was not helping Tristan a great deal.