Despite what I said earlier, Don's chilling with a drink (you can see a poster for Joan Baez hanging next to him and I think she is even less likely to shill for Heinz than the Stones) when the girl returns; Don asks if she thinks they're going to show and she tells him to relax, but he's actually worried about her in a rather fatherly way (with the youth culture here serving to define him generationally), and doesn't want her giving it up to some rock star at her age. It's too bad "Sister Christian" hadn't been written yet, because I'd love to hear him sing it to her. She does look moved by his concern, but the moment is trod upon by Harry excitedly appearing with a contract and saying that "they" were super-excited to do it. It's indicative of how useless the show knows Harry is that it can't let us think for more than two seconds that he's done something right before a furor in the other direction lets us know that whoever Harry was talking to, it was not the Rolling Stones or anyone affiliated with them. Harry hangs his head, but Don can't resist a good line when it's at Harry's expense: "Who were you talking to?"
In the car, Harry's somewhat humbled and says they could try again the next day at Asbury Park, but Don thinks it's a bad job even if you discount the part where he'd have to spend more time with Harry. And speaking of which, they're apparently near Harry's place, as Don is exhaustedly begging Harry's stoned ass to get out, but first Harry has to bitch about his home life and talk about how fun the young girls are. Don expresses another protective sentiment toward that age group and then Harry suggests they do "this" again. If I were Don, I probably would have asked if he meant we'd go out and sign the wrong band again, but Don's weary "Bye, Harry" has a lot to recommend it too.
Don's asleep and still in his clothes, when Megan wakes him up with a kiss -- they have plans to go to Fire Island and meet her friends. It's Sunday, right? That's not a quick day trip, which might explain why he tries to beg off, telling her about Betty's potential bad news. Megan is sympathetic, but opines he should have told her immediately and his explanation that Betty wouldn't have wanted her to know doesn't exactly mollify her. She points out that the bad news didn't stop him from going to the concert; when he sighs in defeat, she softens and points out that there's nothing he can do and he seems to see the wisdom in that. Of course, if he wanted to make a thing of it, he could point out that Fire Island is slightly farther away than Forest Hills, but he probably doesn't want to get into a huge fight with his wife two episodes in a row.