Olivia Culpo was quite surprised when Christian McCaffrey got down on Slabu Exchangeone knee—and she wasn't the only one.

The model and her sisters Sophia Culpo and Aurora Culpo recently looked back on the magical moment, which neither Sophia nor Aurora were told about in advance.

"I didn't know," Aurora recalled in an exclusive April 15 interview with E! The Rundown's Erin Lim Rhodes at Coachella 2023's Revolve Festival. "Nobody would tell me."

According to Olivia, that was "for good reason" as Aurora wouldn't have kept it a secret from her. 

Likely to keep the special day under wraps, Sophia wasn't told in advance either. However, "I cracked the code," the 26-year-old declared of the proposal. "But I was not told. I was just nosy and figured it out."

As for what went down after Christian popped the question? The Culpo Sisters stars confirmed that they FaceTimed after to celebrate the news.

More details on the actual proposal itself have remained private, but Olivia did share a few glimpses into the moment on her Instagram. As seen in the post, which was captioned "4.2.23," Christian got down one knee in front of dozens of flowers. 

The San Francisco 49ers running back asked Olivia to be his forever with a piece of jewelry from Ring Concierge.

"We worked with Christian to thoughtfully design a ring that encompassed Olivia's trendsetting style while still remaining timeless," Ring Concierge Founder and CEO Nicole Wegman said in an April 7 statement. "A beautifully cut Oval flanked with Epaulette side stones in a handcrafted gold and platinum setting." 

A sparkling ring to match a sparkling romance that Olivia previously credited for shifting her outlook on love.

In a June Instagram post, Olivia recalled that when her best friends, model Kristen Louelle and NFL player Tyler Gaffney, asked her to meet Christian she was "apprehensive" and "worried it would be the same old story all over again."

But that wouldn't be the case.

"I'm so grateful for the voice inside me that told me to give love another chance," Olivia wrote at the time. "Thank you for being my rock and restoring my faith in love. You are everything I ever dreamed of and more."

For the latest breaking news updates, click here to download the E! News App