HAILEY Bieber has shown off her toned tummy in a skimpy bikini once more, while rumors she is pregnant continue to grow.

Justin Bieber’s wife is currently on summer vacation with gal pals Kendall Jenner, Justine Skye, and Lori Harvey.

Hailey and friends are celebrating Justine’s 28th birthday, and went all out with a private yacht in Cabo San Lucas, Mexico.

The 26-year-old wore a tiny blue two-piece bikini with white string acccents.

She accessorized the sexy look with a large necklace featuring the aptly-chosen letter B.

Lori, 26, and Justine, 28, soaked up the Mexican sun, as Kendall, 27, treated them to a taste of her 818 Tequila.

Hailey seemed to be passing on the alcohol, opting instead for what appeared to be a box of water.

Lori flaunted her incredible figure in a halter-neck orange bikini with gold hoops and shades.

Justine looked chic in a gingham patterned bikini featuring strawberries.

While Kendall also showed off her supermodel figure wearing a tiny brown and black bikini.

But it was Justin Bieber’s wife with all eyes on her – especially as she held her stomach climbing down a ladder.

Hailey and Justin, 29, are coming up on their fifth wedding anniversary, and the rumors that they’re expanding their family have only escalated.

FOLLOW THE CLUES

There have been many clues surrounding fans theories that Hailey has a bun in the oven.

For one, Stephen Baldwin’s daughter has frequently been caught cradling her belly in various outfits, looking like she’s protecting a baby bump.

Other hints that have surfaced in recent weeks are the model’s interesting food combinations and sudden sweet tooth.

She posted a video of herself indulging in a huge box of pink ring donuts.

And a day later, Hailey shared another clip of her digging into a Krispy Kreme Strawberry Glaze donut.

Hailey also attempted to hide her stomach from cameras with strategically placed details on her outfits and wearing baggy clothing.

BAD TIMING?

Hailey isn’t the only one sparking rumors on her trip.

Fans are wondering if Kendall is engaged to Bad Bunny after her behavior on the trip.

In an Instagram Story, Kendall ditched her clothing as she posed in a greenish bikini set.

The Hulu star covered her face with her yellow cell phone as she teased ample cleavage in the mirror selfie.

She showed off her flat tummy while standing next to the white bed.

In an online thread, eagle-eyed fans spotted a fancy ring on her finger and claimed the reality star was engaged.

One fan pointed out: “Interesting ring.”