- I was playing Riverview one time in the Newbie household, and I got Bob Newbie married to Betty Simovitch. Bob Newbie was part of the active household, the Newbies, while Betty was part of the inactive household, the Simovitch. And from what I remember, Betty Simovitch got her surname changed to Newbie. Awesome, that was exactly what I wanted.
- Then, in Dragon Valley, I played the Burbs, but when I selected John Burb and then clicked on the wedding arch, some moments later, I noticed that John Burb's name would be changed to John Pleasant! No! And it was too late to go to the City Hall, so the very next day, I waited until the City Hall would be open, and tried to get the name change done. I wanted John to keep his birth name, and I wanted Jennifer to change her surname to Burb.

So, basically, from what I understand, if you have an active household and an inactive household, the Sim in the active household would give his/her surname to the partner, while the inactive household's Sim will change his/her surname to that of the active household Sim.

However, things change when both Sims are playable and part of the active household. Whichever Sim selects on the wedding arch and gets married will be the Sim that changes his/her surname to that of his/her spouse?