There are lines under his eyes now, ones that don’t go away even when he sleeps. Gray is starting to sprout from his temples, it takes him a moment or two to get up when he’s been sitting at his laptop. He squints when he tries to read things, pulling it back until he can see the words in front of him. His body is not so rigid anymore and he does not stand to attention as quickly when he wants to get it on.
Dean isn’t there to see Sammy grow old, but he can pretend that he is.