Mathew Weiner gave Peggy Olson and Stan Rizzo a predictable yet unexpected happy ending in Mad Men’s series finale. Anyone who has been watching the series closely saw that Stan fell in love with Peggy long ago. Those skeptics who think Peggy’s love for Stan comes out of nowhere in “Person to Person” [7.13] would do well to remember that we are dealing with a woman who carried a baby inside her body for nine months without noticing until she went into labor. For an expert like Peggy, denying love with all of its butterflies and emotional turbulence would be a snap by comparison.

The chemistry between Stan and Peggy sparks from the moment she takes off her bra in “Waldorf Stories” [4.6]. In this episode, Peggy confronts Stan’s arrogant sexism when she challenges the liberated Art Director to a nude copywriting session. She removes her clothing one piece at time and he follows suit. Soon enough Stan finds it more and more, shall we say “difficult” to concentrate on the medicinal value of Vicks cough drops. They stare each other down and he blinks first. With that duel Peggy and Stan start their friendship off on equal footing. He admires her strength and confidence even while he insults her continuously as they work together at SCDP. They stay in touch when she leaves the agency to join CGC and by the time SCDP and CGC merge they are bickering like an old married couple.

Stan puts the moves on Peggy more than once over the years and she turns him down every time. His tactless immaturity combined with her relationships with Abe and later Ted keeps them apart.

Stan helps Peggy navigate office sexism and improve her management skills. She complains and he listens. By the end of Season Six they are sharing the kind of cozy phone conversations no man would want his wife having with another guy from the office. This is the posture of a man falling in love, not that of a co-worker dispassionately telling his friend her day will get brighter.

Peggy and Stan have always been more than “work husband and work wife.”

The biggest and most recent clue to the depth and permanency of Stan and Peggy’s relationship comes in “Time & Life” [7.11] when she confides in him that she once “followed her heart,” got pregnant and gave the baby up for adoption. This confession, as well as Stan’s sympathetic reaction makes a trusting romantic relationship between the two possible.

In the series finale, Stan advises a drunken Peggy to reject Joan’s offer for a partnership at a production company because she has “a rare talent” for creative work in advertising. She needs to stay at McCann Erickson to develop her gifts a little while longer. His advice prompts Peggy to lash out and call him a failure. Later Peggy apologizes in one of their trademark phone conversations that begins with Peggy’s fear that Don needs her help. Stan tells Peggy to let Don go, though that “doesn’t mean that you don’t care,” the same words Peggy uses in “Time & Life” to describe how she feels about the son she gave away.

Stan, who is in the office down the hall, goes on to tell Peggy that she exasperates him and when they are together “I want to strangle you and then I miss you.” He confesses, “I want to be with you.” A dumbfounded Peggy asks, “What? What did you say?” This declaration comes as such a shock that Stan has to spell it out for her – “I. Want. To. Be. With. You.”

In an effort to grasp the magnitude of what he tells her, she places her hand over her stomach, hyperventilates and gasps, “I can’t breathe.” This reaction mirrors the one Peggy has upon learning she has gone into labor in “The Wheel” [1.13]. In Season One, Peggy ignores massive physical changes to her body including obvious weight gain, for nearly nine months. It takes a doctor placing her hand on her stomach in the midst of a contraction for her to accept that she is in labor. With this in mind, it makes perfect sense that Peggy could fall in love with Stan, her irritating ever-present supporter, and not recognize it for months or even longer.

Stan patiently waits while she processes his “I love you.” We watch Peggy’s love for Stan rush into her body and her brain as she realizes, “You make everything okay.” “It must be true;” she must love him. Peggy’s joyful release of emotions occurs at the moment Stan disappears from the other end of the line. In a romantic moment I did not think Mathew Weiner was capable of writing, Peggy checks the phone connection as Stan appears in her doorway to ask, “You were saying?” Peggy happily repeats, “I Love You” and then in unabashed rom-com style, the two cross the room and share the kind of kiss “Steggy” shippers have been too afraid to hope for.

This classic “love sneaks up on you” story might feel out of character for Mad Men, though we should see it in the context of a series that has always explored genuine emotions such as despair, personal inadequacy and wrenching guilt. Why not love? Stan and Peggy’s relationship will not hold her back professionally, because Stan loves Peggy for her ambition, not despite it. And she can benefit from his belief that, “There’s more to life than work.” If Peggy doesn’t deserve love like this than who does?

Well, maybe Joan, but that’s another conversation.