He doesn't know the particulars of Elise's relationship with the half-lizard and it's not the fault of the siblings.
However, what he does know is that his beloved twin is pregnant for the man that single handedly committed genocide of their people, who Andrei basically sacrificed to give his sister a chance to live a healthy life.
But Andrei starts to crash out, it's valid.
He doesn't know the particulars of Elise's relationship with the half-lizard and it's not the fault of the siblings.
However, what he does know is that his beloved twin is pregnant for the man that single handedly committed genocide of their people, who Andrei basically sacrificed to give his sister a chance to live a healthy life.