To Hex with Sex (1969)

Marvin Swift is a nebbishy schmuck whos a total failure at everything Fired from his job at a brassiere factory he then gets into a pointless argument with his sexy but ditzy fiancee who tells him to go to hell Instead he does the next best thing He meets the devil in a boiler room And the devils a she A very sexy she named Lucibel sans the traditional horns and pointy tail because thats terribly passé today its mod Touched that Marvin is such a screwup she offers to help him but not she says because she wants his soul but because she wants to make him happy So she grants him a wish with no strings attached