Lucifer thinks that Sam's my dad. He...doesn't know the truth.

[as curious as lucifer may have been, jack did his best to keep the truth to himself. to sidestep questions and focus on getting the information he wanted instead. he may not have been particularly good at keeping those transitions smooth, but at least lucifer had played along]

He doesn't know that you're my father either. If he finds out- I don't want him to hurt you.