yes in the episode 'monster at the end of this book' they also show their tattoos, however this picture is not from that episode, but from 'Jus in bello'
We never actually saw Sam and Dean getting the tatuagens but in the season 2 episode 'Born Under A Bad Sign' after Sam was possessed por Meg, at the very end of the episode Bobby gave them both charms to ward off possession in the future. Rather than risk losing the charms, they decided the only permanent way to protect themselves against possession was to have the charm design tattooed on their chests. The charms that Sam and Dean give Hendricksen and the others in 'Jus In Bello' are replicas of the charms that Bobby originally gave them in 'Born Under A Bad Sign'.
And later in Season 4 Episode 18 The Monster At The End Of This Book.
