John Stamos’ Fiancée Caitlin McHugh Debuts Baby Bump on Instagram While Wearing a Sports Bra

It’s (Instagram) official!

On Saturday, John Stamos’ fiancée Caitlin McHugh showed off her baby bump on social media for the first time since the couple announced they are expecting their first child together.

“Good morning baby of mine,” McHugh, 31, wrote alongside a picture of herself caressing her baby bump while wearing a sports bra.

“Enjoying our #babymoon at @miraval_arizona #babybump debut,” she added, revealing that she and Stamos, 54, were taking a romantic vacation together at the Miraval Arizona resort and spa ahead of their baby’s arrival.

Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.

For more coverage, follow our babies magazine on Flipboard.

The reveal came just days after McHugh showed off her growing baby bump when the pair were spotted together at Los Angeles International Airport.

The happy couple walked arm-in-arm and grinned for photographers as McHugh’s growing baby bump peaked out in an oversized green turtleneck sweater.

Until meeting McHugh, Stamos had long reigned as one of Hollywood’s most eligible bachelors. But the actor previously told PEOPLE that he long felt as though something was missing.

“I always wanted to be a dad,” the Fuller House star said of becoming a father for the first time. “I have a youthful thing. People say, ‘Oh, you look young.’ You start believing you’re gonna live to be 150.”

“And then you wake up and go, ‘No, man, this is it. This is not a rehearsal,’ ” he added. “People would say, ‘You should have a child.’ I was like, ‘That ship has sailed.’ ”

It helped that he and McHugh talked about having a baby in the past — and that everything eventually just fell into place.

“We have the same morals and the same values, that all clicked nicely. So we said, ‘Oh, well, maybe we should have a family,’ ” said Stamos, who proposed to the model and actress on Oct. 22 at Disneyland (one of her favorite places) after two years of dating.

“The look on John’s face when I told him we were pregnant was priceless,” McHugh added. “It was the look of a man who has wanted a family of his own but wasn’t sure it was going to happen for him. Now it is!”