Sims not being able to marry is a common issue in the game, usually stemming from one of two things:
a ) Your sim is trying to marry someone in a full household, or they are in a full household themselves. The game won't allow that because both households have to be ready to potentially have a new spouse in them.
b ) Your sim went gravedigging for a new spouse, resurrected them, and the game blocks them from marrying in the homeworld for...reasons I guess.
Neither are my case.
My dynasty heiress made a bad, bad move and fell in love with her married boss. Finally, they decide to make it serious. He breaks up with his wife via text message, and is able to successfully go steady and propose to my heiress (important, please keep that in mind). But the option to get married won't show up.
Other things to consider:
- Their household isn't full. It's seven sims and they're both living together anyways.
- There is another engaged couple in the house, and they're able to marry just fine.
- They have a maxed out relationship, find each other extremely irresistible, and are both Hopeless Romantics to boot.
- I gave him the Clean Slate LTR to see if it did anything. No luck.
- In my experience, breaking up via text message is kind of buggy. Notably, it won't make ex-partners count towards the Heartbreaker LTW. I haven't seen a problem with it when it comes to making proper exes, though. Even in this game, my heiress' half-brother broke up with his steady girlfriend through a text message, and there was nothing blocking him from marrying his new fiancé after that.
- His ex-wife is, oddly, listed as "Ex-Girlfriend" in the relationship panel. Which might be a result of how they broke up.
Any ideas?