It is strongly implied that Lt. Cable (John Kerr) and the island girl Liat (France Nuyen) make love right after they are left alone in the hut by Bloody Mary (Juanita Hall); in the scene immediately following, Cable has his shirt off. The scene was deliberately ambiguous in the 1958 film in order to get past the censors.
The sailors lack the company of women and clearly want sex, but this had to be toned down for the 1958 film so that the censors wouldn't object.