Plot

Beth Ann learns of Rob's infidelity; Simone is blindsided by her Karl's devastating secret; Taylor has an open marriage with Eli.

One Pasadena, Calif. house serves as the focal point for three decades worth of marital strife. In 1963, Beth Ann's life as a doting housewife is upended when she learns of her husband Rob's infidelity. In 1984, socialite Simone is blindsided by her husband Karl's devastating secret. In present day, high-powered lawyer Taylor has an open marriage with husband Eli.—CBS press release

In the opening monologue, the husbands Rob, Karl and Eli, talk about how they met their wives and how happy they were until their wives discovered their secrets.

In 1963, Rob and Beth Ann Stanton move into their mansion in Pasadena following the death of their daughter. After meeting Leo and Sheila Mosconi, Beth Ann overhears Sheila reveal that Leo witnessed Rob kissing a waitress at a diner in Glendale. Beth Ann refuses to believe her husband's infidelity until he calls Beth Ann and tells her he's meeting a client. Beth Ann goes to the diner, and sees Rob kiss the waitress. At Sheila's advice, Beth Ann goes to the diner to confront the waitress, whom she learns is named April. However, Beth Ann loses her nerve and instead befriends April, although she keeps her identity secret from her husband's mistress by saying her name is Sheila.

In 1984, Simone and Karl are hosting a house party. Simone receives an mysterious envelope addressed to her, with a strip of photo booth pictures of Karl kissing a man inside. Simone confronts Karl and wordlessly confesses that there have been others. She demands that he packs. Later, Simone finds Karl slumped on a chair in the bedroom having attempted suicide by overdosing on pills. Simone swiftly calls an ambulance, with the neighbors congregating outside. Simone lies and tells them he fell down the stairs. Her friend, Wanda, who has long resented Simone for always flaunting about money and how perfect her life is while she works through a divorce and drinking problem, doesn't buy her lie. She reveals she was the one who sent the pictures of Karl kissing a man in the envelope. Simone pins her to the ground, with an EMT having to pull them apart. The next day, Naomi's son, Tommy, who was a waiter at the party, admits to Simone that he saw the photos and makes a romantic pass at her. Simone declines his advances, but Tommy states that unlike the men she married, he is in love with her.

In 2019, Taylor and her husband Eli have an open marriage. Taylor breaks the "no hookups in the house" rule when she lets her lover, Jade, stay for the weekend after she is threatened by a dangerous ex-boyfriend, Duke. Eli initially opposes, but eventually agrees when he finds himself becoming attracted to her, and allows her to stay longer if she wanted.

In the closing monologue, the wives Beth Ann, Simone and Taylor talk about a woman's motive for killing, who they would kill and could they get away with it.