This wikiHow teaches you how to put two of your Sims in a relationship with each other in The Sims 4. You can do this naturally by finding a Sim and letting your Sim do the necessary social interactions; if that sounds like too much work, there is a cheat you can use to initiate the relationship.
Steps
Method 1 of 2: Using Social Interactions

Step 1. Understand the limitations
When you try to get two Sims into a relationship, they can't be family, nor can they be the exact opposite of each other's traits.
- While it is technically possible to date two opposite Sims, it is difficult.
- Your Sims' genders don't affect their dating choices.

Step 2. Send your Sim to a social location
If you want your Sim to meet another Sim organically, send them to a club, bar, park, or similar social venue.
You can also just send your Sim out into the street if there are enough Sims around

Step 3. Have your Sim introduce themselves to another Sim
Select the Sim you want to link your Sim to to start a conversation.

Step 4. Look for positive signs
You will see a literal green '+' sign above both your Sim's head and the other Sim's head as they speak; if you see a large amount of this, your Sims are a good match.
- You'll probably also see a few red '-' signs. As long as you see significantly more green positives than red negatives, you're good to go.
- If you see an influx of red negative signs, you'll need to find another Sim to associate your Sim with.

Step 5. Build a friendship between the two Sims
The easiest, least risky way to do this is by talking to the sim through Friendly as the conversation option and then select a dialog option such as Questions about day or Compliment on outfit.
- You want the 'Friendship' bar to be at least 50 percent full; any lower than that, your romantic efforts will fail.
- Avoid flirty (pink) dialogue options when building the friendship.

Step 6. Start flirting
Once your two Sims are friends (e.g. the 'Friendship' bar is at 50 percent or higher), you can start flirting with the other Sim by romance call option and then To flirt to select.

Step 7. Wait to see if the other Sim accepts the flirting
If the other Sim is open to romance, you'll see a pink bar appear below the green "Friendship" bar under both your Sim's and the other Sim's name.
If the pink bar doesn't appear, try building up the 'Friendship' bar some more before trying to flirt again

Step 8. Build up the 'Romance' bar at least 30 percent
Building romance works the same way as building a friendship: select the romance call option and select light options such as To flirt or Compliment appearance.
- Avoid physical actions until the 'Romance' bar has grown a few times. Ideally, you should wait until the bar reaches the 30 percent mark before using physical options.
- If the other Sim reacts unfavorably to something you do, select the To apologize conversation option before proceeding, then proceed with light flirting or complimenting.

Step 9. Ask the Sim to date
Once the 'Romance' bar is at least 30 percent full, select the romance menu option, and select Ask to be a friend or Ask to be a friend in the resulting menu. This usually leads to the Sim becoming your Sim's partner.
If the other Sim reacts badly, flirt again until you've raised the "Romance" bar to about 50 percent, then try again

Step 10. Continue building the relationship
Once your Sim and their partner are dating, you can use the romance keep using options like holding hands, kissing, etc. to build the "Romance" bar.
- Once the "Romance" bar is 50 percent or more full, you can ask the Sim to marry your Sim. If the bar is full enough you even have an option Get married immediately.
Method 2 of 2: Using a cheat

Step 1. Find a Sim you want your Sim to date
Before you can use a cheat to link your two Sims, you need to find the Sim you want your Sim to date.

Step 2. Note the name of the other Sim
You'll need the other Sim's first and last name before you can proceed.

Step 3. Turn on the Cheats console
Press Ctrl+⇧ Shift+C (Windows) or ⌘ Command+⇧ Shift+C (Mac) to do this. You should see a text box appear.

Step 4. Enter the command 'Enable cheats'
Type testingcheats enabled and press ↵ Enter. This will enable cheats for your current Sims 4 game.

Step 5. Enter the 'Adjust relationship' command
You use this command to increase your Sim's "Friendship" and "Romance" bars to 75 percent, enabling romance options without crashing the game. The 'Adjust relationship' command can be entered as follows:
- Type modifyrelationship and press the spacebar.
- Type your Sim's first name and press the spacebar, then enter their last name and press the spacebar.
- Type the first and last name of the Sim you want to date in the same way, making sure to press the spacebar after their last name.
- Type 75 and press the spacebar.
- Type Friendship_Main and press ↵ Enter.
- Repeat this command and replace 'Friendship_Main' with 'Romance_Main'.

Step 6. Start a conversation with the other Sim
Go to the Sim you want to pair your Sim with and start talking to them. Eventually you should see dialog options appear.

Step 7. Ask the Sim to date
Since the two Sims have full 'Friendship' and 'Romance' bars, you can change the dialogue category romance select and direct Ask to be a friend or Asking to be a girlfriend Selecting. This will give your Sims a relationship.
Tips
- If you feel like you need to break up, go to Mean and select To finish. This will make the Sims hate each other. You can also go to Friendly go and Ask to just be friends to clear the 'Romance' bar.
- Try to avoid Sims who have the 'Not Flirty' trait. Their romantic options are limited and they often reject your Sim's romantic advances.