UPDATE 27/2/19: Play through Assassin's Creed Odyssey DLC episode Shadow Heritage now and you'll be able to make clear you are not in love with the game's forced relationship.
But the changes are minimal, and Darius' offspring will still try and cosy up to you anyway. Ew.
What exactly has changed? Well, not much. In the boat leaving scene at the end of the episode the option to make Darius and his offspring stay is now labelled with a heart icon, indicating this is a romance option. If you don't pick it, the cut-scene you get is now edited very slightly to remove one shot of you and Darius' offspring embracing. Finally, the conversation option after the reveal you have had a baby now lets you state "I chose this life to secure the bloodline".