Its addressed a few times actually just earlier on. In the pilot I think it is he says something about how he knew that she wanted him to have the best chance because that’s why Snow White and Prince Charming gave up Emma. Also, he does ask about who his father is at one point which Emma fibs on because she wants him to have hope. I think they also discuss her past in the second episode (or the pilot again) because Regina releases information about her in the newspaper if I remember correctly.
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