The only times Leonor ever feared Desmond were when he was wielding a sword and when he was acting upon her with pure desire.
In those moments she realized how much of a man he was. A terrifying man who had such a hold on her she felt she could do nothing as she was subjected to his touch.
That wasn't to say she didn't want what he was doing to her, but she didn't know how to handle being wanted so badly. He looked at her as if she were the most prized possession. Only then did she feel accepting of being a man's possession.
When they were in such passionate embraces with one another, Desmond became something instinctual as he found which buttons she liked pressed. She felt like a puzzle to be solved and he seemed to get just as much from it as she did.