| Director | Kay Cannon |
|---|---|
| Runtime | 102 min |
| Country | United States |
| Budget | $21 million |
| Box office | $94 million |
Single mother Lisa takes her young daughter, Julie, to her first day of kindergarten. She watches as Julie is befriended by two other girls, Kayla and Sam. Kayla's father Mitchell and Sam's father Hunter introduce themselves and the three become close friends after seeing the bond between their children.
Twelve years later, Julie shares with Kayla and Sam that she plans to lose her virginity to her boyfriend Austin on their upcoming prom night. Kayla pledges to do so as well, though on a casual basis with her lab partner, Connor. Sam, a closeted lesbian who is unsure about her feelings, also joins the pact and arranges to attend the prom with the harmless Chad.
Lisa throws a pre-party for the parents and kids. The girls and their dates then head to the prom, texting each other about their sex pact. The three parents hear Julie's laptop and intercept the messages. Hunter deciphers their emoji codes and uncovers their plan. Lisa and Mitchell rush to stop their daughters; Hunter tries to dissuade them from interfering and shares his intuition that Sam is gay, but upon seeing her force herself to kiss Chad, he becomes determined to stop her from doing something she does not want to do.
Having been told that the after-party would be at Austin's house, the parents go there but find only Austin's parents Ron and Cathy engaging in sex games. Ron reveals that the after-party is at a lake house but refuses to give the address. The trio realizes that Mitchell's wife Marcie may have it and retrieve the address against her wishes, as she supports Kayla's right to make her own decisions. However, the parents are unable to catch their daughters when the partygoers disperse to avoid the police.
As the group struggles to find their daughters, it becomes clear that each parent has their own motivation: Mitchell is in denial over his daughter growing up, Hunter feels guilty for neglecting Sam during his bitter divorce from her cheating mother, and Lisa is struggling to let go of her only child who secretly plans to leave for UCLA against her wishes; Lisa is confronted with this when Julie angrily states that she is going to UCLA to get away from Lisa's clinginess.
Knowing that Austin and Ron have been texting, the parents return to Ron's house to steal his phone. Encountering the couple playing a blindfolded sex game, Hunter and Mitchell are forced to play along as Lisa steals the phone, which reveals that the girls are at a hotel. There, a drunk Sam goes to bed with Chad but decides she does not want to have sex (he still prematurely ejaculates anyway). Kayla and Connor go to bed, but she also changes her mind and they limit their intimacy to Connor performing cunnilingus on Kayla.
Mitch finds Kayla with Connor and throws him against the wall, infuriating Kayla. Mitch confesses his struggles with her becoming a woman, his good intentions ultimately making amends with Kayla. Hunter finds Sam and they also share a tender moment, where he reveals that a good night was the best he could give her in return for his neglect. Sam comes out to her father, who is deeply moved at being the first person she told. Lisa sneaks into Julie and Austin's room and, realizing how much they clearly love each other, leaves unnoticed. On her father's advice, Sam comes out to Julie and Kayla, who embrace her and affirm their lifelong friendships. They leave Sam with her crush Angelica who shares a romantic kiss with her. Mitch, Lisa and Hunter acknowledge their own friendships have been strengthened and drink to their daughters' futures.
Three months later, the parents celebrate the departure of Sam, Kayla, Julie and Austin as they depart on a road trip to drop off Austin and Julie at UCLA. As they leave, Lisa starts receiving the girls' group text, filled with plans to use drugs and have unprotected sex. The parents panic until the girls text that it was a prank, and send a final "I love you" to them.