what is going on with 邪恶力量 no 更多 laughter times and there are flaws now how could Bobbie be possessed in season 5 if he knew aboout them so well why didn't he protect himself with the tattoo like Sam and dean?

Ah well, there's still laughter, it's just a little 更多 scattered because of, well, 你 know
The Apocalypse.
And Bobby isn't a tattoo kinda guy. Maybe the got him in his sleep when he didn't have his charm on. It's the Apocalypse, the demons are getting smarter.

Watch S05ep07 and 你 will laugh a lot. I think Bobby is too worried about both Winchesters to watch his own back. He's still alive and tutoring them, ain't he?