Gaze at the face of infidelity.

A woman on TikTok revealed that she discovered her boyfriend was cheating on her simply by sitting in the passenger seat of his car.

In @joiederouen’s short March 5 video that has over 11 million views, she zoomed in on his dashboard mirror to show the very distinct markings left by an Octoboddy smartphone accessory on the glass.

An Octobuddy is a phone case outfitted with suction cups to stick on flat surfaces and frequently employed by drivers and passengers to film themselves in the car — including, say, an unsuspecting girlfriend’s GRWM video.

So, JoJo surmised that the Octobuddy marks meant her boyfriend was unfaithful.

“Crazy because this is how I found out about the other girl,” she captioned the 7-second clip.

Other TikTokers commented on the video and shared their own stories of how they found out about their partner cheating on them.

“I found out from dreams which led me to investigate,” one person wrote.

“Haha found out when I saw “Madison’s iPhone” on his car Bluetooth. ,” someone else wrote.

“I saw a text on Christmas Day. 32 years of marriage,” another comment read.

A fourth person said, “I found out from a shoe print on the inside of the windshield.”

“I found out because I found the wrapper for a bouquet of flowers on the floor, that I didn’t get,” another TikToker shared.

The amount of cheating stories in the comments section sparked concern from TikTokers.

“Damn these comments are harsh. I’m sending love to all who need it,” someone wrote.

“Whole comment section needs therapy ,” another person said.

Back in 2022, a woman named Aurie Louisse shared a TikTok explaining that you can pull down the passenger side visor mirror halfway to uncover if your partner is cheating.

The trick means that if a woman gets into the passenger side and checks her make-up in the visor mirror, she’ll probably close it again when she’s finished – meaning the person who set up the trap will know when they check the car.