Most of the male characters in Don Draper had a lot of mistresses, Pete also had many indiscretions.

Pete was among the most dynamic of the Sterling-Cooper team, and it was always comedy gold to see him punished for his hubris. However, his character arc was also one of the most touching of the show - he found his happy ending with Trudy after many hard lessons about the ad guy lifestyle, a neat ending to his Mad Men story, but not before he left a string of affairs in his wake.

7 Peggy

Season 1

Pete sleeps with Peggy, played by Mad Men’s Elisabeth Moss, twice in season 1 of Mad Men, both before and after his marriage to Trudy. The first time is in the pilot episode, “Smoke Gets In Your Eyes”. Their first interaction on Peggy’s first day sees Pete being very rude about her appearance, showing his entitlement. Later in the episode, after his bachelor party, he shows up at Peggy’s apartment and sleeps with her. Another time Peggy and Pete have sex is on an office sofa in episode 8, “The Hobo Code”, when the pair arrive early to work.

Unlike Pete’s other affairs, it had consequences with Peggy. Viewers see Peggy in a doctor’s office being examined for a birth control pill prescription early in season 1, following advice from Joan. However, during her affair with Pete, she has not been taking the pill for long enough for it to be effective. Nine months later, Peggy learns she is pregnant only when she gives birth to a baby boy. Peggy didn’t know she was pregnant in Mad Men because of a combination of weight gain, a sheltered upbringing, and intense denial.

6 The Au Pair

Season 3

One of Pete’s most horrifying affairs in Mad Men is when he sleeps with a neighbor’s German au pair, Gudrun. This moment is among the most shameless things Pete Campbell did in the show. According to Pete actor Vincent Kartheiser, the coercion shown in the scene was not scripted, and the other character was meant to kiss him back (per The Wall Street Journal). Regardless of whether or not it was intentional, it certainly comes across as nonconsensual, making it one of the most uncomfortable Pete scenes.

There is also a power difference in the interaction, since Pete has helped the au pair repair a damaged gown. He claims he deserves a reward for the gesture. Ultimately, Gudrun leaves her job because of Pete’s behavior. This happens while Trudy is away in the season 3 episode “Souvenir”, showing the steady escalation of his cheating behavior in getting involved with someone so close to home.

5 A Fellow Driver’s Ed Student

Season 5

The episode “Signal 30” was one of the strongest episodes of Mad Men season 5. A combination of the brilliant symbolic writing paired with John Slattery’s directing skills made it lauded by critics. The episode also documents a steady emasculation of Pete Campbell and all of his insecurities coming to a head. Pete thinks he has fixed a leaking faucet early in the episode, and it later bursts, and Don “Superman” Draper has to swoop in, making it symbolic of Pete’s shortcomings in his personal and professional life.

Don’s prediction in the pilot, “nobody will like you”, comes true at this point in Pete’s arc. Lane calls him a “grimy little pimp” and challenges him to fisticuffs, and he certainly had it coming. Not least because he starts flirting with a teenage girl he met in his Driver’s Ed class. The pair seem to get along, but his attempt at forming an affair with her was cut off when a jock her own age with the nickname “Handsome” swoops in to chat her up, echoing Don intervening with the tap.

4 A Prostitute

Season 5

Almost unbelievably, Pete’s night with the prostitute happened in the very same episode as his attempted affair with his Driver’s Ed classmate, “Signal 30”. It seems to be a direct result of the rejection. Pete’s fantasy of choice with the prostitute is telling. The prostitute goes through several options of types of women she could embody for him, and only when she says “you’re my king” does he finally agree. This seems to be a direct reaction to his perceived powerlessness in the rest of the episode.

Pete has been bested in DIY by Don and in combat by Lane...

Pete has been bested in DIY by Don and in combat by Lane, and his attempt to seduce the teenage girl failed, so all that is left for him to do is engage in a power fantasy. It reads as a rock bottom in Pete’s character development, not because of the prostitute herself, but because of Trudy’s father. Seeing him at the brothel blows his lifestyle wide open, which is humiliating for Trudy.

3 His Neighbor

Season 6

Pete's affair with his and Trudy’s neighbor, Brenda, in the season 6 episode “The Doorway” represented a particularly brazen and unsettling development in his marital infidelities. While Pete had certainly strayed before, engaging with someone living in such close proximity to his and Trudy's home highlighted a significant escalation in his reckless behavior. It underscored a growing sense of entitlement and a shocking disregard for the potential consequences.

The episode doesn't offer a definitive moment of confession. However, given Trudy's sharp intellect and her familiarity with Pete's character, it's plausible she pieced the truth together through a combination of factors. The neighbor's distressed appearance at their door after being beaten by her husband created an atmosphere of unease. Perhaps Pete’s reluctance to leave the women alone could have triggered Trudy's suspicions. In the following episode, she puts Peter in his place.

2 Beth Dawes

Season 5

One of the most memorable and tragic of Pete Campbell’s affairs in Mad Men was his entanglement with the married Beth Dawes, played by Alexis Bledel. Bledel shows her range playing this vulnerable young woman in an unhappy marriage. Pete becomes obsessed with the idea of saving Beth from her misery, and their affair is intense and short-lived.

Beth is the wife of insurance salesman Howard Dawes, who rides the train daily with Pete. While Beth’s motivation for the affair seems to be for the thrill and an escape from her suburban malaise, Pete seems to crave the feeling of falling in love. This is highlighted by Beth saying, “I thought we had the same problem, but I was wrong.” The most tragic part of the affair is her not recognize Pete after she undergoes her routine electric shock treatment.

1 His Real Estate Agent

Season 7

Bonnie Whiteside is Pete’s girlfriend when he is living in LA in season 7. This part of the show sees Pete take in a very different working environment from New York. At this point, he and Trudy are separated, but because Trudy refuses to “be a failure”, they are not divorced. While the separation means his involvement with the charismatic real estate agent isn’t an affair, it wasn’t a lasting connection.

The pair only briefly dated. However, it looked to be getting fairly serious when they visited New York together. Bonnie really wanted to meet his and Trudy’s daughter, Tammy, and she even bought her a Barbie doll, but Pete did not want to merge his two worlds. They got into a fight and broke up, but their brief relationship was a significant moment in Pete’s slow transformation in Mad Men. Their split made Pete realize what he really wanted in life.

Source: The Wall Street Journal