No option to 'propose marriage'.

I thought it was because my sims had a cheater reputation (lol) that the option was not appearing. Then I noticed with two other sims that are faithful that it still wont appear and they are in a steady relationship already. I cleaned my sim's reputation with generation's lifetime reward choice and still nothing. Is this a common bug? Is there a solution? I really do not want to uninstall and reinstall the game, it takes forever to do so. It all happened after I updated the game and I recently bought and downloaded Generations.