"It will be okay, Sam." He chuckled softly, deciding Sam really was too much of a worrier, though Dean did all his worrying internally, rather than talking about it like Sam did. Just enjoying the weight of Sam's arm against him, Dean settled down easily, scraping his blunt fingernails against Sam's forearm.
Closing his eyes, Dean just hummed Hey Jude to try to get Sam to shut up and settle down. It had always been what settled Dean to sleep when Mary sang it, and Dean had hummed it to Sam a lot when they were kids. It was a painful memory, but still a good one.