He doesn't know yet, and I'm not gonna spill the beans to 'im, but you oughta at least try to look out for him. Kid hasn't known about bein' part demon for long and was raised by demon hunters, so I'm bettin' he'll need a bit of help coming fully to terms with it.

Not to mention he's gonna start askin' questions eventually, since someone else went and spilled to him that he and I both have the blood of Sparda. He finds out the truth, it'll be less trouble for all of us if he doesn't think of his old man as an irredeemable douchebag.