In the Odyssey, blood is most definitely thicker than water. Your deeds (or misdeed) don't just reflect on you; they reflect on the honor and reputation (kleos, if you want to be fancy) of your entire family—living, dead, and unborn. That's why Telemachos is actually kind of mad at his father for not just dying in battle; and that's why Achilleus is so interested in hearing about his son when Odysseus comes to the Underworld. You think you're under a lot of pressure from your parents? Try having a Greek hero for a dad.
The father-son relationship is more important to the family structure of Odyssey than the husband-wife relationship.
In the Odyssey, servants are part of the family. Disloyal servants are like treacherous family members, not deceitful employees.