After Freya responds, "Aren't we all." To Mimir's comment about starting a family. Kratos looking at Freya at 1:59 - 2:02 like : "Where's the "O" button?"
After his conversation with Angrboda in which she said the boy needs discipline, I get the impression Kratos would be quietly cheering his son on if he pursued Angrboda. Angrboda would make Atreus a good wife and would bring out the best of Atreus.