Adrian Grenier Gets Buck Naked to Celebrate His 40th Birthday

'Entourage' Star Adrian Grenier Goes Naked to Celebrate 40th Bir…

‘Sister Wives’: Kody Shares His Hopes for Christine and Janelle …

'Sister Wives': Robyn 'Struggles' With Living Monogamously With …

'90 Day Fiancé’: Michael Reveals Affair With Another American Wo…

'Seeking Brother Husband' Showcases Women Seeking Multiple Male …

Inside the ‘NCIS’ Crossover Event With OG, 'Hawaiʻi’ and ‘Los An…

'MILF Manor': First Look at TLC's New Dating Series (Exclusive)

Golden Globes: Why Jamie Lee Curtis Called Out Paul Walter Hause…

Mischa Barton and Rachel Bilson Tear Up Watching Marissa's Death…

Jessica Betts ‘So Proud of’ and ‘Constantly in Awe’ of Wife Niec…

Brad Pitt Reveals Surprising Hobby He Shares With Daughter Shiloh

Steven Spielberg Shares Surprising Secret Behind Ke Huy Quan's C…

'Golden Globes': Janelle James on Sitting Near Brad Pitt and 'Ab…

'Sister Wives' Star Meri Brown Calls Out Media for Misinformatio…

'Abbott Elementary': Gregory's Dad Comes to Town (Exclusive)

Brad Pitt Was the Most Popular Actor at 2023 Golden Globe Awards

Christine Taylor and David Lascher Revisit Their Secret 'Hey Dud…

'The Last Of Us' Showrunner Craig Mazin on Plans After Season 1 …

Tatjana Patitz, Iconic '90s Supermodel, Dead at 56
Adrian Grenier literally striped down to his birthday suit.
For his 40th birthday on Sunday, the Entourage alum spent time in the Hamptons, where he giddily cannonballed into the pool wearing, well, nothing.
WATCH: Adrian Grenier Presented With the Paul Walker Ocean Leadership Award
Grenier documented the naked adventure, writing on Instagram, "Jumping into my 40's wearing my birthday suit."
The caption wasn't all cheekiness, however. He also added an uplifting caption about improving the world.
"#makeasplash with me this year and let's make the world a better place together by showing love and compassion for ourselves, each other, and the natural world around us," he added.
MORE: Adrian Grenier Helps Birds Fly
While the Marauders star rarely undresses on social media, he does frequently share inspirational words about the causes he holds dear to his heart, including animal rights and environmental conservation. Last month, the New Mexico native even called himself out for wasting food after enjoying a healthy meal at a restaurant.
RELATED: Madonna Celebrates In Her Birthday Suit
"Here's an environmentalist's dilemma...the food was fine but I'm full and have no one to share it with. I don't want to contribute to the almost 50% food waste in our country," he wrote.
"But this place uses plastic to-go containers and [I] don't want to further pollute our precious planet and oceans with plastic. I can't wait for our civilization to evolve implement a better food / waste system so that I don't have to worry so much. I'm sorry I was a part of this sad moment. #foodwaste."
Grenier is such a big environmentalist that he was honored by Meadow Walker, the daughter of the late Paul Walker, with the Paul Walker Ocean Leadership Award in June. See a piece of the presentation in the video below.