Soulmate aspiration and BFF
I had a sim with the Soulmate aspiration and got the goal "Get married to BFF". By the time I got the goal, I was in a relationship with Soulmate status. We got Engaged through the conversation option...
Forum Discussion
I just completed this aspiration. Here is what you have to do. First, develop a friendship AND a relationship with another sim. Once you have your friendship to the highest point, you will be given an option in the "friendly" interactions menu for "become best friends". Once you are married AND best friends, you will fulfill this part of the aspiration. I hope this helped.
