Liam Hemsworth Celebrates Big Brother Chris' Birthday With a Hilarious Instagram Post

Getty Images

Just a little brotherly love!

Liam Hemsworth had the best birthday post ever to celebrate his big brother, Chris Hemsworth, who turns 34 on Aug. 11.

WATCH: EXCLUSIVE: Chris Hemsworth Says His Kids Are 'Not Impressed' by His Film Career: They're Like 'Whatever'

"Happy birthday Chrisso! Love u ya massive jerk ;) xox @chrishemsworth #bathtime #rubberducky," Liam wrote on Thursday, alongside a hilarious pic of Chris shirtless in a pool, with what looks like a small towel on his head and a rubber duck.

Chris' Avengers co-star, Jeremy Renner, commented on the snap, writing,"Bday bubbles for ol Hemi…. Cheers my man!!!"

RELATED: Chris Hemsworth Shares Heartwarming Pic of Twin Sons Holding Hands

ET caught up with the Thor: Ragnarok star during San Diego Comic-Con last month, where he and Mark Ruffalo opened up about filming the latest installment and their favorite way to get some sleep.

See what they had to say in the video below.