Well, in terms of The Book of Passion, a new OGL sourcebook that's up on Kickstarter, that would be Christina Stiles. We might be a couple days removed from Valentine's Day, but there's no reason you can't get some intimacy into your fantasy games.
From the campaign:
The Book of Passion, by authors Will Wells and Margherita Tramontano, adds role-playing rules for love and sex to your OGL 3.75 campaign. Long-time game designer/editor/developer, Christina Stiles, will publish the book via Misfit Studios. The 208-page book will reflect the most recently available 3.75 classes from the rule set's main publisher, if stretch goals are met.
The Kickstarter campaign is up and running now. It's set to go for another 27 days.