That being said, a source close to Chyna told ET that their nuptials will most likely be a big event. "The proposal was big," the source explained. "It's clear Rob likes big gestures."
ET also caught up with Kardashian, 29, who revealed his fiancée is his No. 1 priority.
"I'm just chilling and making sure she's straight," he said.
During the event, Chyna took to Instagram to share a pic of herself sporting a beige halter dress and relaxing in a cabana located in the club's VIP area. Her fiancé went for a more casual look, rocking a polo shirt, dark pants and his signature Los Angeles Dodgers hat.
The official Instagram page for Sky Beach Club also shared a pic of the happy couple, which gave fans a peek at Chyna's burgeoning belly.
Chyna -- who is already mother to 3-year-old King Cairo, whom she shares with Kylie Jenner's ex-boyfriend, Tyga -- hasn't been shy about showing off her baby bump ever since she announced she was expecting.
On Wednesday, she put her bare belly on full display in a selfie posted to her social media accounts. Watch the video below to hear more.