Actor Josh Brolin says he gave hot new wellness trend “perineum sunning” a whirl — with disastrous results that left his “pucker hole” sunburned.

The “No Country for Old Men” actor revealed the effect of tanning his bum in a Black Friday Instagram post.

“My pucker hole is crazy burned and I was going to spend the day shopping with my family and instead I’m icing and using aloe and burn creams because of the severity of the pain,” Brolin wrote next to a photo of a naked man lying on his back with his legs in the air as the sun kisses his posterior.

“I don’t know who the f-ck thought of this stupid shit but f-ck you nonetheless. Seriously.”

Most of the world was introduced to the practice of “perineum sunning” last month, when an Instagram health influencer who goes by Ra of Earth posted a now-viral video of three naked men lying on the grass with their legs up, exposing their backsides to the sun.

“In a mere 30 seconds of sunlight on your butthole, you will receive more energy from this electric node than you would in an entire day being outside with your clothes on,” Ra of Earth said in the video.