Sam had tensed when Dean went for his jacket pocket, just a little. He didn't know what his brother could have there.

...The holy water was NOT what he was expecting.

Sam had just opened his mouth when he got splashed, which turned into coughing because he'd been trying to breathe, too. After a moment, he reached up and wiped his hand down his face. "Feel better now?" he asked Dean, cocking an eyebrow at his brother.