Actor Josh Brolin has a message for today’s youth: Tanning your taint isn’t a good idea.
The actor learned that hard lesson a few days ago after he engaged in “perineum sunning,” a new trend in which people expose the area between the anus and the sex organs to the sun, according to the New York Post.
One practitioner, who calls herself Metaphysical Meagan, claims that perineum sunning can regulate hormones as well as sleep patterns.
The man who plays Thanos in the Marvel Cinematic Universe saw the Post story and decided to try it out.
It wasn’t such a hot idea, he admitted on Instagram this weekend, and he hopes others don’t make the same mistake:
“Tried this perineum sunning that I’ve been hearing about and my suggestion is DO NOT do it as long as I did.
“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.
“I don’t know who the fuck thought of this stupid shit but fuck you nonetheless. Seriously.”
New York-based dermatologist Jeremy Fenton isn’t surprised Brolin feels a little burned by the experience.
“This area is vulnerable for two reasons,” Fenton told Yahoo. “Number one, it is an area that has not received much sun exposure in most people, thus it would be lacking in the body’s normal response to sun exposure that protects it from future sunburn, such as producing pigment. Number two, it is sensitive skin to begin with, so any burn in that area may be more significant and more uncomfortable.”
Fenton warns people who insist on baring their buns to the sun that they could increase their chance of getting a sunburn.
“There is some evidence to suggest that the genitals may be more susceptible to skin cancer than other areas of the body,” Fenton said. “A skin cancer developing in this area may be more difficult to detect because people don’t regularly view this area on themselves.”
This article originally appeared on HuffPost.