Wooyoung and San, the '99 liners' of the group ATEEZ, have become a hot topic after revealing the cool behind-the-scenes story of their friendship tattoo.

Previously, a video titled "Forever Bickering Girls and Boys Night" was uploaded to makeup artist Risabae's official YouTube channel. In the video, ATEEZ's same-aged members Wooyoung and San, along with Patricia, appeared as guests to enjoy a pajama party and show off their honest wit.

When Risabae asked the two, "Do you guys meet up and hang out often?" Wooyoung and San proved their family-like bond by replying, "Even our parents are extremely close." The two then drew attention by mentioning their "friendship tattoo," which is famous among fans.

The answer to the question about how they decided to get the friendship tattoo was surprisingly simple and clear. They revealed that without any grand reason or long hesitation, one simply suggested, "I want to get this, what do you think?" and the other coolly replied, "Sure," before going straight to get the tattoo, causing surprise.

At this, Patricia jokingly asked, "You weren't forced to do it, were you?" to which San laughed and replied, "I did it because I wanted to as well," once again confirming their strong bond.

The broadcast also featured a "battle of exposures" that highlighted their "bestie" chemistry. While discussing situations where they get upset with each other, Wooyoung mentioned, "San has a specific aegyo (cute) expression he makes when he feels unfairly treated," referring to the so-called "Eogul-hing" (pouting) face. San reenacted this on the spot, making the set burst into laughter.

Meanwhile, ATEEZ, the group to which Wooyoung and San belong, continues to enjoy global popularity with their intense performances and unrivaled worldview.