Chris Hemsworth teases brother Liam about his physique on his birthday

One day, maybe, possibly, the Hemsworth brothers will finally get their bodies into shape.

Well, of course, the "Avengers" and "Isn't It Romantic" stars are already among the most buff Hollywood actors we've got.

And that's the joke behind Chris Hemsworth's message to his younger brother, Liam, who turned 32 on Thursday. In honor of his birthday, Chris, 38, posted this Instagram picture of a totally ripped Liam in the gym with the message, "Happy birthday @liamhemsworth hopefully this is the year you finally get in shape and take care of yourself. To help with your transformation I’m gonna gift you 10% off a @centrfit membership #familydiscount love you"

So, you know, just some light sibling teasing.

Centr, for reference, is the elder Hemsworth's digital health and fitness program, which offers remote workouts and activities. And while we don't doubt those two hit the gym hard and on a regular basis, a shirtless shot of their father from 2018 proves they also have excellent genes.

Related video: Chris Hemsworth hilariously trolls brother Liam Hemsworth

Meanwhile, the birthday boy had nothing but nice things to say on Instagram, where he posted a short video shot in (where else) the gym. In the caption he wrote, "Thanks to everyone who sent me birthday wishes! Love you all! These cakes that I also got sent should really help on my health and fitness journey! Cheers guys!"

Be sure to swipe through to see a picture of Liam surrounded by flowers, three cakes, three doughnuts and some balloons!

He also had a special shoutout for Chris and the 10% discount offer. "What a gift!" he said. "The gift of health! ... That's just the kick in the a— I needed to continue on my fitness journey."

Of course, Chris wrote back in the comments with laughing emojis.

Who doesn't love a Hemsworth?