[ Cas throws a mildly irriated glance over his shoulder at Dean. ]

I know it's.. uhm. Been a while since you walked in on me in any state of undress, but... I assure you I've only decorated myself in... debauchery and scars.

[ Which is his roundabout way of saying that he's never gotten any tattoos, voluntary or otherwise. ]

Someone did offer, once, with uh... a hot needle. I declined. Didn't, hm. See the appeal, really.