The 30-year-old pregnant "Younger" actress took a tropical getaway with Luca, her 6-year-old son with ex-husband Mike Comrie, prior to her baby girl's due date.
Duff shared a photo Saturday on Instagram of herself lounging on a pool chair with Luca. The expectant mom showed off her baby bump in a simple black bikini.
"Max relax," she captioned the picture.
Duff also posted a video Sunday on Instagram Stories of Luca giving her a foot rub in their hotel room.
"Wow, this is nice service!" she tells her son.
"You have to give me twenty bucks," Luca jokingly answers.
"What? You didn't specify that before you started. I thought this was a donation," Duff responds.
FOLLOW REALITY TV WORLD ON THE ALL-NEW GOOGLE NEWS!
Reality TV World is now available on the all-new Google News app and website. Click here to visit our Google News page, and then click FOLLOW to add us as a news source!
Duff announced in June she's expecting a daughter with boyfriend Matthew Koma.
She shared Luca's idea for a baby name during an interview with "The Late Late Show with James Corden" the same month.
"Luca thinks Cofont Croissant is, like, the coolest name," the actress said.
"When I refer to it as 'Cofont,' and I'm like, 'That would be so cool, nobody at school's gonna be named Cofont,' and he's like, "Croissant. Cofont Croissant.' It, like, goes together. There's no separating the two," she added.
Copyright 2018 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.