Supernatural fans have had to suspend our disbelief for wilder things in the past than Sam and Dena getting secondary anti-possession tattoos on their forearms.
Still, wouldn’t it be fun if episodes of Supernatural’s final season that haven’t filmed yet could incorporate the real-life tattoos?
Sam and Dean got their anti-possession tattoos on their chests, so even a match of the mark wouldn’t be identical to the show since the actors got the tattoos on their arms.