First appeared in Interzone. It was runner-up in the Interzone Readers Poll, reprinted in genre retrospectives by John Clute, David Pringle & Simon Ounsley, David G. Hartwell, and Kathryn Cramer. From the collection, Sexual Chemistry and Other Tales of the Biotech Revolution.
Giovanni Cassanova, a rather unattractive man, is a genetic genius. He creates a protein to be secreted by sweat glands that turns on the opposite sex. He uses it to gain lovers. Once his secret escapes, he is in multiple legal and love troubles.
The tale is largely expository. The appeal is following out the permutations of an idea--a chemical that enhances sexual attractiveness--and how that impacts society over time. It makes an interesting thought experiment.