I think adding the option for a romantic relationship would be great. I don't think it should be one a player is required to participate in but for many of us it would add great depth and enjoyment to the gameplay.

To have a warrior who's believed in you from your merger beginnings and fought beside you fall in love with you seems expected. To experience the dialog between of warm words and warm nights would only add an element of joy in this otherwise unforgiving environment.

Then to birth and rear a child whos life is forged on the battlefield from birth is the makings of an epic King or Queen. "I leaned to count by counting the victims of my parents swords, and learned quickly." Sounds like a cool story to me.