Sometimes Sean would think that she was a bit manipulative, but she was his sister after all, so he let it slide. Who could have imagined the face on the surveillance footage?
When his biological sister first came back to the family, he thought all sisters were like Serena, all mind games and clinginess, maybe even relentless. Fresh to high society, she likely felt timid and out of place.
At that time, he was nursing a serious injury, hanging onto life by a thread, and had no energy to deal with her or cater to her feelings.
He dreaded a girl's tears - what if she was a crybaby?
As word got around that she was becoming the family's darling, he figured she must be playing a game more sophisticated than Serena's. Otherwise, how could she have won everyone over so quickly?
Turned out his sis had real skills, a unique charm that captivated everyone. She was nothing like the "sister" in his head.
