I play with two different family of one Sims, in the same town (bridgeport).
I played in both game in the hope for Sims A to meet Sims B or vice versa. No chance.
I read a bit online and on forums and apparently, you can just show up to one's home and ring the bell. Since it's in an apartment building, a list of the Sims living there appear when I do that, but in either game (A or B) the other sims don't show up where it should be.
So I tried the ''call him with your cellphone'' thing, and my other Sims don't show up in the list of the other.
I went to ''edit town'' and I see all my households (A and B) with some basic money in their account (not the one they have in the advanced game, but probably the amount they had when I first created them). So I was in the active game A, went to edit town, and saw that I could copy household B in my town. But from what I understand, that sims wouldn't be the one I've been playing in the B game.
So are A and B living in two parallel worlds that can't meet ? That's sad, because that's a feature I really liked in Sims 2, being able to make two households merge after a while through some imaginary love story.
Is there a way to do it in Sims 3 ?