He stared at Celine coldly and asked, "Who is he?"
Although she was being stared at coldly, Celine didn't tense up at all. Instead, she looked directly into Arthur's eyes as she responded, "He is someone who is way out of your league." Celine's voice was filled with confidence and she didn't look like she was lying at all.
Even Katelyn herself was surprised by how confident Celine was in Jack. But, she had no choice but to think that Celine's confidence in such a situation was nothing but foolishness. Being brave and confident wasn't bad. But, it depended in the situation that one was currently in.
True to her thoughts, the mood that Arthur was in at the moment plummeted further at the mention that he wasn't as good as the boyfriend that Celine was mentioning.