Mom-to-be Lauren Burnham is showing — and glowing

Lauren Burnham is showing — and glowing!

In a sweet photo that the 26-year-old reality star’s fiancé Arie Luyendyk Jr. posted to his Instagram on Friday, the mom-to-be can be seen showing off her baby bump in an adorable white two-piece swimsuit.

The dad-to-be, 37, captured her looking in a mirror with her blonde locks pulled back into a ponytail as she ties her bikini into place.

“Have you ever seen anything more beautiful?” he captioned the photo with the heart eyes emoji. BurnhamArie Luyendyk/Instagram
Lauren Burnham
| Credit: Arie Luyendyk/Instagram

He added that they were “Packing for Hawaii!!!!” where they will be officially tying the knot on Jan. 12. He also tagged their in-utero little one’s Instagram account.

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

Arie Luyendyk
| Credit: Arie Luyendyk Jr./Instagram

The day after Christmas, Luyendyk shared a sweet photograph of Burnham getting an ultrasound. Responding to a fan who asked, “What is most exciting about being a dad?,” the reality star wrote: “So many things but mostly doing this together with her.”

The former Bachelor added, “I can’t wait to meet this little person that has already grabbed our hearts.”

As for when the engaged couple will announce the sex of their baby, Luyendyk Jr. teased, “The plan is to reveal on The Bachelor premiere.”

Recalling the moment he learned he was going to be a father, the star wrote, “Honestly I had tears in my eyes and Lauren was in shock haha,” also sharing a photo of six different pregnancy tests.

RELATED VIDEO: Arie Luyendyk Jr. and Lauren Burnham Celebrate at The Venetian Resort Las Vegas

Arie Luyendyk Jr. and Lauren Burnham
| Credit: Lauren Burnham/Instagram

In addition, Luyendyk Jr. revealed he and his fiancée are counting down the days until their little one’s arrival. “5 months 8 days,” he shared.

The Bachelor couple announced they were pregnant via an Instagram post in November.

“We’re so excited,” said Burnham, who has said that despite “really bad” morning sickness, things are going smoothly.

Added Luyendyk: “I’ve always wanted to be a dad and I know Lauren is going to be such a great mom. I see it all in front of me, and that is really gratifying.”