He studies Amilyn's face. Her confusion, so sincere, says as much as her words. So he really was such a shame to his mother that she had to weave lies about what happened, even back when she sent him away. Ben Solo, always the afterthought.

"Ah... So that's all there is to it." With bite in his voice, he adds, "You should ask her for the whole story, the next time you see her."