Apparently at the same time, from the fact that the office is darkened, Peggy steals a cigarette out of one of the desks in the main area and lights up. I'm pretty sure Don hasn't smoked in any of the flashbacks we've seen, so if he only started when he came to SC, this seems to be another brick in the road to Peggy becoming Don.
The next day, Anna brings Don, who's out on the porch, a beer, and Don jokes about how loose the pants she gave him are. She laughs and says they belonged to "Harold," whom she kicked out, "even though old ladies shouldn't be picky." She needs to hang out with Alice Cooper. Don sincerely says it's beautiful out there, and Anna laughs that it's fitting he likes the porch, as he paid for it. Wow. Between her and Adam, it's a good thing Don's such a higher-up at SC, or he and Betty and the kids would be living in that tiny apartment. Anna tells him she thinks about him sometimes, just to wonder what he's up to, before asking how old his kids are now. As he tells her they're eight and five, his mood darkens, which can happen when people are so gauche as to bring up the subject of you having abandoned your children. Anna tells him if he doesn't want to talk about what happened, he doesn't have to, but she wants him to know he can. "I always felt that we met so that both of our lives could be better. That's just how it is between us." Don confesses that he's ruined everything with his wife and kids, and even mentions Adam, saying he came to find him, and he told him to go away. She tells him she didn't know he had a brother, but given what happened to him it's probably just as well. Don, clearly struggling to figure himself out for once, says he's told Anna things he's never told Betty, and wonders why it has to be that way. Anna's response is wise in its way: "You love her. You don't have to tell her everything. I'm sure there are things about her you don't know." Don certainly doesn't want to go down that road, as jealous as he's proven himself on numerous occasions to be, and when Anna asks if he'd like to call home, he says no. "That would just confuse things." And I'm sure your children feel they have everything figured out at the moment. She asks what he's going to do, and he confesses he doesn't know. "I have been watching my life. It's right there. And I keep scratching at it, trying to get into it. I can't." Don has never looked so sad and vulnerable, and I don't say it enough but Jon Hamm is doing an amazing job here. Anna looks at him kindly and says she's sorry, and the two sit in silence for a moment before we go to commercial.