Zac Efron melts hearts everywhere as he wishes his younger sister a happy birthday on Instagram

Zac Efron melted the hearts of his 56.7 million Instagram followers on Monday when he posted a birthday tribute to his baby sister Olivia.

The 33-year-old heartthrob – who sent heartbeats earlier this month when he worked out shirtless – posted a pair of cute photos which showed him holding his adorable 2-year-old brother.

Olivia appears to be the daughter of Zac’s father, David Efron, and his second wife, making little Olivia Zac’s half-sister.

“Happy birthday little sister,” the High School Musical star wrote, captioning an adorable pair of images.

The first photo shows Zac holding Olivia as she gazes lovingly at his mustachioed, chiseled face, prompting widespread speculation that the star has undergone plastic surgery.

The little girl’s floral headband held her golden curls in place as she marveled at her big brother, who wore a festive green boutonniere.

Zac’s neatly cut hair has been styled lightly with gel, giving him an effortless look that pairs well with his rugged appearance.

Always tanned to perfection, the Baywatch star sported a sexy holiday glow.

If Zac’s first photo didn’t make his fans faint, then his next photo was sure to be fatal.

Olivia snuggled into her older brother’s chest as Zac hugged her and kissed her head.

‘How is this man not married yet?!’ commented a super fan of Efron.

‘Can you please father my children?’ asked one loving follower.

‘Do you want to hold me like this?’ gushed another suitor, echoing many of the loving sentiments that spilled over from his comments section.

The main man is reportedly still single since his split from model/waitress Vanessa Valladares.

Beyond making millions of people swoon on Instagram, Zac’s top priority seems to be his career as he has a slew of big projects on the go.

The A-lister recently filmed a romantic comedy for Netflix called The Family Affair starring 23-year-old Joey King and 55-year-old Nicole Kidman.

And the star is currently hard at work on the wrestling biopic The Iron Claw starring 33-year-old Lily James.

Never missing an opportunity to muscle up for a role, Efron has made jaws drop with his muscular looks as he takes on the role of heavyweight champion Kevin Von Erich.

Zac has come a long way from his teen idol days, making the treacherous leap from Disney to mainstream and becoming a proper movie star in the process.

But one thing that hasn’t changed is its ability to make millions dizzy.

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