Dean looked at Cas who was just stepping out of the way? His lips pursed as he tried to think this one through; there were too many questions and not enough answers. The fact that the sigils, glyphs, whatever he damn things were called looked familiar didn't help. They looked almost like some of the stuff he'd used to keep out angels or send them on their merry ways. He glanced back at Cas.
Dinah's stepping up to knock on doors or whatever, announcing they were there, didn't sit right with Dean either. He didn't like being polite and knocking if something big was going down inside. Especially something big dealing with his brother. A brow rose in question, but he didn't say anything. Instead he made sure he had very easy access to his sidearm.
Later he'd apologize to Dinah for not looking at her bite. He was pretty sure the bite could cause trouble for her in the future. He didn't say anything, which wasn't that usual for the older Winchester. Instead he waited, just barely.