Sirena, foot stamping sword waving hellion, takes her sister's place as wife to the virile Regan van der Rhys, Dutch colonizer of Java in "Captive Passions" by Fern Michaels. By day she is his quiet pious wife, but by night she sinks all his shipping and taunts him with her tawniness and her thighs.  It's 1977 and thighs are very in.  Buckles are swashed.  Also there is a lot of nutmeg.