Considering everything that Cas has done for the boys

[Anu]

Don't you think that they should at least help Cas out in his war or if so not disturb him all the time? And take realization that he is actually fighting a freakin' war! Cas helped the boys during the apocalypse a lot, he even rebelled for them. He tried to help Sam get his soul back too. Shouldn't the boys even try to help? They're supposed to be his friends after all.

[Kar.]

You're right, but what can they do? Not to mention they're pretty swamped with tracking down Eve.

[Anno_Domini]

I bet Castiel will man up in "The Man Who Would Be King". While telling all of his little secrets, he will probably tell Sam and Dean how he really feels.

[halvor311]

They have offered to help. Cas said that there was nothing they could do. It was in the episode where Cas was B.A. and burned Crowley's bones. I think it was called Caged Heat.