All ATEEZ members are close to each other, but San and Woo Young are especially close.
They always referred to one another as 'amicus usque ad aras', which is a Latin phrase meaning a friend to the very end.

At that time, fans noticed 'amicus usque ad aras' tattooed on his right thigh.
Then, Woo Young was also spotted with the exact same tattoo on his right thigh.
It turned out their 'amicus usque ad aras' tattoos were a matching tattoo.

SAN answered, "No, I don't regret getting a matching friendship tattoo with Woo Young at all."

(Credit= 'vantablack_1126' 'ateezofficial' Twitter, Online Community, 'ATEEZ' Universe)
(SBS Star)