"I wish I could."
Kyle truly wishes he could stab that woman, but seeing that Anna is already considering Lucia as her precious friend, Kyle does not have the heart to harm Lucia. He is afraid that he would make Anna angry at him, and he does not want that to happen.
"As a Robertson, you get what you want not to wish what you want," Elijah said in a stern voice. The tone on his if full of pride. But Kyle couldn't care less of what his grandfather thinks.
These past days all he can hear from his grandfather is Robertson that, Robertson this, everything is about the Robertson family, and Kyle is sick of hearing the same thing over and over again.