No Propose Marriage Option

Hi, 

I just recently had this problem with my sims. I had my sim first travel to China where she met Ho Sung Kim. They hit it off but  he was married. She invited him to visit as a foreigner several times and that went fine. I had them go on dates and eventually my sim asked him to leave his wife. Then they got engaged. For some reason the interaction was not there to let them get married. They could woohoo and find each other irresistable and all that but no marriage. This went on for several days. I tried breaking up their engagment and restarting the relationship and that still did not work. They would only go back to romantic interest. I tried moving them out of the home, splitting the home up, switching households and going back to them, I tried quitting and saving the game, I even had Ho Sung go back to his ex to see if that was the problem. Nothing worked. I got so tired of this that I was about to give up this sim family. Finally on my last attempt I moved them with the new interaction to move to a different town. I moved them from Isla Paradise to Sunset Valley and then the interaction was finally there to get married. Hopefully that  helps.