Oh, Dean will smack Sam out of his wallowing and he'll try to help with solutions, but he'll admit that there's not much Sam can do with Ruby a world away.

Dean has experienced purgatory. He knows that most of the monsters belong there, just like most monsters need to be hunted. However, there have been too many in their lives that didn't belong there like Garth, Ruby, and Benny.

Okay. Dean is definitely shocked by Sam's reveal. It takes him a moment to respond because even though Dean spent most of his life sleeping around, it's not something you do once you commit to someone. "You just landed in bed with her, Sammy? Tripped and your dick went inside her?" He takes a deep breath and shakes his head. "You don't just land in bed with someone. You meant it or you didn't. How did Ruby find out?"