Lady Issala Adaar is my Wifey! Do I get her name? That's like family.
(A drawing of Sera and Issala in so many flowers. "Sera Adaar" is written in every blank space.)

I have to say, I enjoyed Sera writing "Cullenly and Rowanly" in her journal

Well, I could see the problem with Sera if you're playing as Lavellan, given her racist views on elves during the vanilla game (although she does seem to grow more as a person in Trespasser), along with marriage being limited to a ceremony conducted by the Chantry (which can be another issue if you're playing as a non-Andrastian). I didn't have that issue because most of the people surrounding my character repeatedly denigrated my culture and religious views, so I didn't have much incentivize to engage in a relationship with anyone.
Eh, I don't know. My parents got married in a church despite not being religious.
Anyway, my only major complaint about the marriage was that it was done secretly for some reason. I really would have liked the companions to have been there, and comment, in a perfect world. But even just being there without talking would have been much better. Still, it gave me unprecedented feels.

Bonus points for the mabari 
I also feel bad for the people who would have liked that option, or at least to bring it up with their romance, but couldn't
I thought it was particularly odd for Cass and Josephine 