How about a bitter ex that accidentally got pregnant during her honeymoon with one of your Sims? And your sim immediately divorced her after learning the news as they were completely broke and couldn’t afford to take care of their newest addition. It was just too much to deal with, so your sim moved on. It’s now your sim’s new wedding day, and this bitter ex shows up to ruin the big day and cause chaos as her revenge. Wow, such drama!
If this answer seems oddly specific it’s inspired by another forum post ?. I couldn’t help myself.