He did kiss her on New Year's Eve. It was New Year's Eve! It was customary to kiss your date at the stroke of midnight. So technically Cassie was not his date for the evening but he had been dancing with her at midnight. She looked incredible in her dress and she deserved to be kissed at midnight. It would have been bad luck for him not to, wouldn't it? Not that he was superstitious at all.
After that kiss that night Charles found himself thinking about kissing her more. So even if him kissing her initially was his fault, the kissing following was all on her. If she hadn't been a good kisser then maybe he wouldn't have thought about it again. Or if she didn't smell so good when she came over or look so attractive.
Though it didn't matter how it started or why it continued. Charles was very much enjoying the time they spent together, even if it didn't end with kissing. But more often than not, that was exactly how it ended. For the first time in a really long time Charles was happy. And spending time with Cassie had a lot to do with that. The kissing didn't hurt either.
He wasn't the kind of guy to have a large ego but occasionally it popped up in moments of flirty banter with Cassie. It had been awhile since he found himself in this position and it wasn't as easy as everyone said. Charles laughed at her response, giving her a sideways glance. "I think you're giving me a break from Chris," he corrected her. He was teasing of course. He loved his brother a lot but they were certainly two different personalities.