Nathan Fillion reveals massive back tattoo: 'One poor choice'

What happens on vacation, doesn't always stay on vacation.

Nathan Fillion is taking home a new back snake tattoo "The Rookie" actor, 48, debuted the ink Sunday on social media along with a caption in which he seemingly questions his choice.

POST MALONE CELEBRATES THE NEW YEAR WITH HUGE FACE TATTOO

“One hellova holiday. Good times on the beach (not pictured), fun times with my family (not pictured), and maybe one poor choice (above),” he wrote.

“This trip was one for the books. Now, I suppose we have to go back to work? Please correct me if I’m wrong. Please,” Fillion added.

His "Rookie" co-star Titius Makin Jr. asked if the serpent tat was actually real -- “Is it bad that I think this is dope & want it to be real."

KAT VON D ADDRESSES BACKLASH OVER NEW BLACKOUT TATTOO

In another video from his beach getaway, Fillion showed off a chest tattoo while sailing with some wild dolphins. "Another incredible first for me. Dolphin encounter in the wild. Quite a day," he wrote.

He didn't clarify if the ink is for an upcoming role. According to IMDB, he is currently filming the action-adventure movie "The Suicide Squad" due out in 2021.