He waits until they're in their bedroom, girls sleeping next door, everything blessedly, mercifully quiet, to let himself collapse.
He doesn't make it to the bed. He goes down onto the floor in a kind of controlled slide, jacket half off, still in his boots, eyes closed because the lids literally feel too heavy. He's shaking. He might be weeping with relief and release if he had the energy. As it is he feels almost comatose, on his knees on the floor with his head tipped back, one hand bracing himself against the foot of the bed.
He just needs to stay here a few minutes. Just needs to get himself together enough to get naked and fall into bed. Enough to be here and present for Neil, because he's not the only one who watched Dean Winchester die tonight.
Just needs to try to understand what it means that this is finally over.