Do you have sex on the brain?

Here’s an optical illusion that is said to reveal the dirty minds among its onlookers.

“Message d’Amour des Dauphins” — translated in English to “Message of Love From The Dolphins” — was drawn by Swiss artist Sandro del-Prete in 1987 and has been exposing spectators’ sexual proclivities ever since.

The optical illusion shows a jar emblazoned with an image, but not everyone is in agreement as to what exactly the image depicts.

[Warning: Spoilers below]

Many adults spot a kinky couple in a raunchy embrace, with a naked women being grabbed by a man from behind.

However, others see seven dolphins swimming in the image on the jar and are unable to identify the nude lovers at all.

Some believe the optical illusion reveals a lot about a person’s “mindset” and has been causing controversy for decades.

“Is this a pervert test?” one worried viewer wrote on a website for “skeptics” back in 2011, after one critic claimed it exposed whether or not a person’s mind was “corrupted.”

Others, including the artist, del-Prete, believe that what viewers see may have more to do with their lived experience, rather than whether a mind has been “corrupted.” According to his website, it’s been posited children may be more likely to spot the dolphins first, as a provocative image of two lovers may not ring a bell in their recent memory.

Meanwhile, the erotic optical illusion may have inadvertently exposed some secret memories for a group of naughty nuns.

Author Al Seckel wrote in 2004 that the same image was exhibited at the Museum of Science in Boston before a group of nuns objected to its public display, saying they could clearly see the nude lovers.

The nuns were reportedly “silenced” when curators told them that “one’s perception [of the image] is based upon past experience.”