I'm not gonna lie, I would LOVE to have another companion who is already in a relationship. I don't mind someone who's just not interested, but I'd like to see more people who are already in relationships. In DA, out of the companions, only Aveline is currently married while she's a companion. Then we have Isabela and Oghren who are widowed (although I guess technically, Oghren was married still to Branka when he first joins and then could be married to Felsi again in DA: A).
I liked that we had Jaheira and Khalid who were already married and together in BG. Although, we all know how well that turned out for Khalid......