That was great:
Jealous, maybe, but not petty. The little voice in the back of her mind prodded at her. She managed to ignore it most of the time, particularly when faced with Clark's disapproval of Lex. She always felt that it was a criticism of her, and as such her defensive instincts always kicked in at the slightest hint that he was judging her taste in men. How, after all, could her partner possibly know more about Lex Luthor than she did? It was just as well for Clark that he hadn't said anything.
But there remained, now, just a little tug of doubt. It was probably silly. What possible reason could Clark have other than jealousy to feel the way he did? He'd never explained his feelings to her. Didn't that show that he had nothing solid on which to base his suspicions?