6. Don and Miss Farrell
Right, so, this affair was just all kinds of wrong. Miss Farrell is Sally's elementary school teacher, who, in episode 3x07, initiates a suggestive conversation with Don while they're at a parent-student field trip, program thing about the solar eclipse. They strike up a conversation about summer vacations easily enough, and Miss Farrell presumptuously asks - more or less - if he's about to make a pass at her. Don's taken aback by her abrupt, forward nature. We can tell that that wasn't his intention. But then he thinks about it... and then he's turned on by the fact that she says bluntly how all the dads hit on her. It's not the first interaction between these two characters, but it's the scene in which the infidelity seed is planted in Don's brain. What makes it so... I don't want to use the word "despicable" here but... Let's go with "tactless." What makes it so tactless is that Miss Farrell waltzes in with her curly hair and ribbons, flirting with all the dads and then taking care of their kids, exploiting the entire teenage boy fantasy about their hot teacher. She is in no way the victim of these men's passes - which would be empowering, if there weren't a previous episode in which she has a sit-down parent-teacher conference with a married, expecting Betty in play. When Miss Farrell is done with her conversation, she jumps over to Sally to engage in the school project they're doing. Don watches, curiosity - and I'm sure plenty of dirty thoughts - piqued. Actually, I think both of them should be slapped in this scene. This particular affair crosses, like, a hundred lines that ought never to be crossed.