The Sims 4's Romance system is one of the things the developers did very well with the game.
There are plentiful social interactions in that category, and excellent animations for each of them.
Some of the negatives can make them almost impossible to pull off, although you can always try to turn the other Sim's mood around by making them playful through jokes, being happy and using Brighten Day, or any other Emotion-related Socials.
Those that pop up contextually, like give advice, can soothe negative moods instantly.
There are several things that improve the success rate of Romantic Social Interactions. Romantic Success: Emotion Emotion can have a major impact on how often your Sim's Romantic Socials are accepted.
First up is the context of the exchange, with Steamy Exchange giving the greatest bonus ( 12). If your Romantic Interest has any of the positive moods, they'll be more likely to succeed.
Finding Love If you want your Sim to get along with their future husband or wife, then find a Sim that has Traits that you like.