I know I read a story on fanfiction.net, but can not find it now.
What I remember is this. Castiel went into a bar to wait for Dean and Sam. While there he had one beer. But it seems someone managed to slip something into it, drugging him. When he went outside, he was grabbed by a gang that proceeded to rape him. He his found by Dean, and he and Sam take Cas back to a hotel to take care of him. Dean goes to find the gang to extract justice.
Later on, the same gang finds Dean and does the same thing to him, this time with Cas coming to the rescue.

Sound familer? By the way, it is gen, and NOT slash. Not into slash....I know...weird right? I mean, in this fandom?

Anyways...thanks in advance.