The songs Detente (Wait) and Cuando Estemos Juntos (When We're Together) are sultry. The videos are steamy. And the stars—Latin pop singers Tatiana and Johnny—are sizzling. Especially when they lock in the kind of passionate video embrace that makes Jimmy Swaggart want to unplug your MTV. "Feel how this great love grows," Johnny purrs. But Swaggart needn't fume; Tatiana's reply is swift and heartbreakingly short: "Wait!" The medium may be hot, but the message is, "Cool it."

Designed to encourage premarital responsibility among Latin American teens, the songs have generated surprising interest—Cuando was No. 1 in Mexico and went Top 10 in 16 other countries. The songs have also generated controversy, thanks to their provocative style. But "if kids see sexy people saying no, they can say no, too," reasons 17-year-old Tatiana Chapa de Palacios, a Mexican-born pop singer and actress. "Besides," says Puerto Rico's Johnny Lozada, 18, a former member of Menudo, "if they saw a couple of nerds onscreen, they wouldn't listen."

That was exactly the strategy Patrick Coleman had in mind when the 38-year-old director of Johns Hopkins University's Population Communication Services Project decided a warning against "children having children" should be made hip. With the help of former RCA records executive Frank Segura, he got the songs written, recorded and distributed. Now the pair are planning spin-off projects in other languages. Says Segura, "This is a lot more satisfying than promoting Billy Idol."