<P> Baby discovers that Johnny's dance partner, Penny Johnson, is pregnant by Robbie Gould, a womanizing waiter who is cheating on Baby's older sister, Lisa . Baby borrows money from her father to pay for Penny's illegal abortion without explaining why . Penny eventually accepts the money but identifies another issue . Penny will miss her weekly dance performance if she goes for the abortion, forfeiting Penny's and Johnny's salary for the season . Billy suggests that Baby fill in for her . Johnny's scoffing overcomes Baby's initial resistance . Billy and Penny insist that Johnny can teach anyone to dance . Johnny teaches Baby the mambo, and the two spend several awkward practice sessions together . Baby gradually improves, and they develop a romantic attraction . </P> <P> Billy takes Penny to an abortionist . Johnny's and Baby's performance is mostly successful, although Baby is too nervous to accomplish the dance's climactic lift . Johnny and Baby return to Kellerman's and find Penny in agony . Billy explains that the "doctor" turned out to be a back - alley hack . Baby brings her father to help Penny . Johnny claims responsibility for her pregnancy out of fear that Penny will be fired if her relationship with Robbie is revealed . Jake treats Penny but forbids Baby from associating with Johnny or his friends . After Baby apologizes to Johnny for her father's behavior, they dance and have sex . At breakfast, Jake tells his family they will be leaving the resort early but relents when they object . Baby continues to see Johnny despite her father's warning . She pulls Johnny off the footpath when her father is nearby, and Johnny is hurt that she will not stand up for him . After Robbie taunts them, Johnny assaults him . </P> <P> Due to his growing feelings for Baby, Johnny refuses payment for sex with another guest, Vivian Pressman . Vivian has sex with Robbie in his cabin, and Lisa accidentally interrupts them . When Vivian leaves the cabin the next morning, she sees Baby leave Johnny's cabin . Over breakfast, Max and Neil Kellerman reveal to the Housemans that Moe Pressman's wallet was stolen . Vivian accuses Johnny of the theft in a fit of jealousy . Johnny is unable to provide a verifiable alibi, to protect his relationship with Baby . To save Johnny from being fired, Baby confesses she was with him . Johnny is cleared of the theft after it is revealed that two elderly guests, Mr. and Mrs. Schumacher, stole several guests' wallets . Max fires Johnny anyway for having a fraternizing affair with Baby . Baby and Johnny embrace and bid farewell to each other, saying they will never regret their affair . Baby pointedly apologizes to Jake for lying about her relationship with Johnny but not for the relationship itself . </P> <P> Baby and her parents watch the end - of - season talent show . Jake gives Robbie a tip in an envelope . Robbie thanks Jake, and reveals that he got Penny pregnant; Jake yanks the envelope back . Staff and guests (including Lisa) are singing the closing song together when Johnny interrupts them to perform the last dance of the season . Johnny leads Baby onstage and makes a brief speech about how "Frances" has made him a better man . Baby and Johnny dance a more provocative version of their mambo duet, and the other "dirty dancers" join in . Baby runs to Johnny and executes the elusive lift move they practiced . The dirty dancers pull guests from their seats to join in the celebration . Jake apologizes to Johnny for thinking he got Penny pregnant and reconciles with Baby . All dance joyously to "(I've Had) The Time of My Life". </P>

When does johnny fall in love with baby