On Saturday, Scott Disick and Sofia Richie not only took their relationship to the Instagram official level, but they also celebrated receiving a "congratulations" cake by kissing on the lips in front of their friends.

Scott Disick and Sofia Richie Get a Congratulations Dessert and Become Instagram Official

On Saturday, Scott Disick and Sofia Richie not only took their relationship to the Instagram official level, but they also celebrated receiving a “congratulations” cake by kissing on the lips in front of their friends.

During their trip to Miami, the Keeping Up with the Kardashians star, 34, made things Instagram official by posting a sweet picture of himself and Richie, 19, on his Instagram story. In the photo, the two are posing together in front of a blue sky, with Disick’s face hiding behind Richie’s.

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Richie posted a similar photo on her Instagram story with the couple posing with their arms around each other.

On Saturday night, the two were spotted receiving a desert at dinner on a plate on which the words “Congratulations Scott & Sophia” were written. (The name was misspelled.)

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Image zoom Scott Disick/Instagram

Image zoom Sofia Richie/Instagram

One of their friends shared a video of the moment on Instagram, capturing Disick and Richie kissing each other on the lips.

Richie later posted a photo of the plate on her Snapchat with lines of what appears to be chocolate crossing out the congratulatory message.

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Image zoom Scott Disick/Instagram

The trip comes one week after a source told PEOPLE that Disick and Richie have been “inseparable.”

“They’re spending every day together,” said the source of the pair, who grabbed coffee in Calabasas last Friday before hitting up Beverly Hills, where they shopped and were later spotted at the Montage Hotel.

“Sofia seems smitten,” added the source. “It’s obvious that she looks up to Scott — she constantly giggles around him. They are very flirty.”

RELATED VIDEO: Scott Disick and Sofia Richie ‘Are Inseparable,’ Says Source

In May, the daughter of musician Lionel Richie was pictured cuddling up to Disick aboard a yacht in the south of France during the Cannes Film Festival. Since then, the pair has spent time together in Las Vegas and Malibu, despite Richie squashing relationship rumors at the end of May when she tweeted: “Just so everyone can get their panties out of their a–es, Scott and I are just homies.”