He sees she is broken, he knows it. But he's a mad god so he lets it slip into the back of his mind when she makes no protest about coming to his bed. He learns every corner of her body, claiming it with his hands, his mouth and the rest of his anatomy. He takes it for granted that he has her heart even after the promise he broke. And takes it for granted that she would know, she has is.
He's such a wild god, he lets himself be distracted by nymphs, by satyrs, by any who want him really. He'll notice but not register the jealous looks she gives, the confusion, the rage.
Then he finds her in the arms of another.
Then it clicks, like a key unlocking things he should have already known.