Jaime was not unaware of it. He knew fear, much as people commented often that the Kingslayer showed no signs of it. He knew what it looked like, when Cersei had teased him in their youth, bet him he wouldn't pull the mane of the Lions in Casterly Rock. He'd known fear. He hadn't done it. He'd never done it. It was Cersei that had been the risk taker of the two of them. It wasn't until he'd grown and become what he was, the great Lion of Lannister so feared and hated through Westros, and beyond he supposed, thinking of the exiled Targaryans left fatherless by his sword.
He knew fear. And Trish was scared. But not just of him. She was crying. Jaime couldn't help himself, it was an instinctive movement, reaching up to wipe her tears away. "You're afraid aren't you." he asked quietly. "I know not of what...but you are. I can see it." and she was trying to hide it, from him. Probably from herself. And then she spoke of this other person. One she hated so completely and he just let her talk.
She didn't say as much as she could have of course.
"Well your kindness is appreciated." he finally said, after she'd told him all she was going to of this other person she'd hated. A person that had hurt her deeply. "We won't talk further of it. We can wash the cloak, you can show me how and we don't need to mention anything of the past. Yours or mine. This world can be a new beginning can't it. Where your hate and the name of Kingslayer can die and stay buried. Would you like that?" he asked her. He felt bad for her, wanted to protect her as any good knight would. And sometimes he was that, a good knight, not troubled by his past or his forbidden love for his sister. Oh he wished her here every moment. But in her absence he could be what he had once sworn to be