Kaia Gerber Shares Rare Photo With Boyfriend Jacob Elordi on Valentine's Day

Kaia Gerber/Instagram. Inset: Kevin Winter/Getty; Steven Ferdman/Getty

Kaia Gerber and Jacob Elordi are taking their relationship to the next level.

While the model, 19, and Euphoria actor, 23, have kept their romance private for the past few months, Gerber showed her boyfriend some love on social media for Valentine's Day on Sunday.

Gerber — who is the daughter of Cindy Crawford and Rande Gerber — shared a rare photo with Elordi on her Instagram Story. The sweet pic showed the couple relaxing on the beach as they lounged side-by-side on a daybed each reading a book. Gerber didn't caption the photo but simply added a red heart emoji to the Instagram Story slide.

The model also posted a solo shot of Elordi on her Instagram Story where she called him her "valentine." She later posted a close-up shot of a bouquet of red, pink and white roses that appeared to be from her boyfriend and said, "lucky girl... 🥰."

Kaia Gerber/Instagram

Elordi and Gerber's latest relationship milestone comes after a source exclusively told PEOPLE that the Australian actor has "embraced Kaia's Malibu life and seems to love it as much as she does."

The couple, who first became romantically linked in early September, have been staying together at the home of Gerber's parents.

"They rarely leave Malibu and instead enjoy the beach, go hiking and meet up with friends for dinner," the source said at the time.

Steven Ferdman/Getty Images; Brendon Thorne/Getty Images

"Jacob is very sweet to Kaia. They are always very loving and cute together," added the source. "It's obvious that Cindy and Rande approve of Jacob too. They spend a lot of time together."

In October, the pair made things Instagram official by posting photos of their epic Halloween couple's costume.

RELATED: Kaia Gerber 'Looked Very Happy' During Date Night with Jacob Elordi in Malibu, Source Says

Channeling Elvis Presley and his ex-wife Priscilla Presley for their fun holiday look, Elordi donned a blue suit with a white collar and a pair of aviator glasses for the occasion, which he made complete with his hair styled to look reminiscent of the late king of rock and roll.

Meanwhile, Gerber sported a skin-tight purple top and matching pants that she accessorized with retro winged black eyeliner and voluminous hair, as she posed beside her actor beau for the selection of photos.

RELATED: Kaia Gerber and Jacob Elordi Make Relationship Instagram Official with Couple's Halloween Costume

Elordi and Gerber first became romantically linked in early September when they were spotted dining at the same restaurant, Nobu Malibu. Later that month, the couple were then seen holding hands as they made their way to dinner in New York City.

One onlooker who saw the pair hand-in-hand while out in Manhattan in September told PEOPLE they appeared "comfortable" with each other.

"Their fingers were interlocked, and they seemed very comfortable together," said the onlooker. "At one point they weren't holding hands and Kaia grabbed his and they went on their merry way. They looked happy."

Since then, the couple continued to spark their romance rumors as they later went on to vacation in Los Cabos, Mexico, with Gerber's parents, Cindy Crawford and Rande Gerber later that month.

Gerber previously dated Pete Davidson while Elordi was most recently linked to his Emmy-winning Euphoria costar Zendaya.