Human Sexuality by Kristin Lance
It's an opportunity of a lifetime, and it'll save my brother's life. But I have to give myself over to an alien, which is something I never thought I would do. The Aunga'ri claim they're on earth to protect the human race, but most humans suspect they have another agenda. They've taken over our leadership, our military, and more. And now their advanced medical science claims to have a cure for cancer. If I work for them. If I train them in the one thing that they do not understand: Human Sexuality.
Content Warning: Explicit sex