I don’t think there’s enough of a moral personality to Bran in that sense in that he sits there and passes judgment on what relationships are okay and who you love.
I don’t think Bran’s really sitting there judging whether having sex with your aunt is right or not.
I think what actually bothers is not the actual act of the incest but more the fact that this is going to be very very dangerous.
I don’t think it’ll be such an issue for Bran because I think he takes quite an objective look at the world, and mainly all he’s concerned with is whether people are getting killed and whether there are people lying.