Zac Efron Sets 'Ovaries On Fire' With Latest Instagram Post!

If Zac Efron hugging koala bears wasn't enough to melt hearts on Instagram, he just posted the most precious pictures of him holding his baby sister for her third birthday and this has made ovaries melt, globally.

His tender expression is also turning his female fans into nothing more than mush, as many of his IG followers begged and pleaded with him to marry them, or at least be their baby daddy!

Before we get to Efron and his little sister, here's him and another little buddy, an adorable Koala bear.

Efron and his buddies are on Netflix with a nature documentary, "Down to Earth", now in its second season. In the nature series, Efron travels to different parts of the world with wellness expert Darin Olien to explore healthy, sustainable ways to live. Sometimes he has guest stars, like Anna Kendrick as well.

Fans seem to like the series and left comments on Efron's Instagram praising it and him:

"I wish "down to earth" would be used in schools to teach the next generations all these things to keep the earth alive as long as possible. season 2 is great again 👏👏👏 I hope we get to see more of this in the future. I love it 💚"

"Just opened Netflix up and the promo was on. My 4-year-old was like “whoa, can we watch that?” Don’t have to ask me twice!"

"He’s so handsome ❤️❤️ my goodness that smile gets me every time."

"It’s always a good morning when Zac Efron makes an IG post and his shirt is off lol. Can’t wait to watch!"

"Was this guy just born with abs?"

Meanwhile, his holding the Koala seemed to set off his female fans into a frenzy!

"Zac, hold me like you’re holding that koala 🐨! Love you, Daddy."

"Please marry me love you Zack."

"Zac becoming a DADDY!!!"

"I’ve never wanted to be a koala so badly! Jk love down to earth!! Thank you for doing it."

Clearly, Efron doing nature documentaries is a good idea, given that so many people suddenly get interested in saving the Earth! Have a look for yourself...

On Monday, Efron shared an Instagram carousel of two photos where the "High School Musical" alum wished his little sister a happy birthday. In the photos, Efron, wearing a lovely green shirt, holds his sister, Olivia, in his arms. In the first photo, she looks at him with a sweet smile, and in the second, they share a snuggle as he places a sweet kiss on her head.

Efron also wished her in the caption, writing, "Happy bday lil sis". Olivia is Efron's three-year-old step-sister, the daughter of Zac’s father, David Efron, and his second wife. Efron's mother Starla Baskett and his dad divorced in 2016, and the ex-couple share two sons, 35-year-old Zac and 30-year-old Dylan Efron.

Dylan also commented under the post, “I think we spoiled her", ending it with a heart emoji.

The brother and sister looked picture-perfect as Olivia wore a crocheted floral headband and a pink dress, offsetting Efron's green shirt and mustache.

Here go more pictures of the little princess, this time with Dylan!

Efron is quite the hunk for his new movie, "Iron Claw" but it's not just the muscles that work on the fairer sex, so to speak. It seems seeing a little girl in Efron's rather manly arms is sending many on Instagram into a dead swoon, and lighting every female fan's biological timebomb!

The comments border from the awestruck to the downright salacious:

"My ovaries oh dear god"

"Can you pls be the father of my children?"

"Everyone wants you to be their baby daddy now Z!! Ok, they wanted it before-- but, you know."

"Well, my ovaries are on fire now.. thanks for nothing."

These comments also seemed to miff some on Instagram as one soul tried to shut them down, saying, "Some of these women need to chill. you could be his mother...some of you are married, bro. ew! smh. like yes, he's handsome but it's a sweet innocent picture with his family stop making it about your ovaries."

Here's more fuel for that, err, fire as one fan wrote, "her look says it all!"