When Don's biological little girl Sally is visiting her prospective boarding school, she invites her childhood friend Glen over to impress the mean girls of Miss Porter's who are hosting her. (On a side note, CW should totally give Sally a spin-off about her boarding school exploits.)
The protective relationship Glen has over Sally – "She's like my sister," he tells his pal when he tries to put the moves on Sally – is touching, and reminiscent of what Don once had with Peggy.
Peggy and Ted's romance may have been upsetting everyone in the office, causing Michael Ginsberg to faking bathroom breaks to get away from them and a look of annoyance permanently etched on Joan's face whenever they were around. But sooner or later Don's condescension will lose him the respect of everyone who once admired him. And there's nothing sadder to watch on Father's Day than Daddy Draper curled up by himself in an alcohol-induced fetal position.