The first thing they do the day after the world is saved and will never have to be saved again, when it's set right and everyone is alive and Jack has promised not to stay out on "new deity training" with Amara past his curfew, is collapse into bed. A decade and a half's worth of exhaustion hit them both all at once, and it doesn't matter much that the bed isn't big enough or that Dean only got halfway through kicking off his clothes. Sam flops on top of his brother, and Dean mutters about him being the size of a horse, and for the first time in a very long time, they both get a good night's sleep.