So i saw all SPN episodes..i think o.O the thing is i can't really remember..do we get to see the boys doing that tatoo they have? 또는 they just appear with it?

No, we don't see the boys actually getting the 문신 done. Back in Season 2, in "Born Under a Bad Sign", Meg managed to possess Sam and made a 봉인, 인감 on his forearm so she could not be exorcised from him. Bobby burned the 봉인, 인감 off Sam's arm, and Meg hightailed it. At the end of the ep, Bobby gives the boys charm amulets to prevent their ever being able to be possessed again. Then on to Season 3, "Jus in Bello", where they first show their tattoos. It is generally assumed that the 문신 are the same 디자인 that was on the charms, therefore ensuring that possession would be impossible. :DD

No there is no episode of them getting the tattos. It ones of that shouldn't (and doesn't) waste time in an episode but rather happend inbetween.

i dont show 당신 sam and dean getting their tatoo done