It made perfect sense to me. Katy is singing about allowing someone to inflict themselves on her, to have a closer relationship. She's speaking of a woman who would do anything for the man she loves. And Kanye is singing about how great he perceives himself to be.
At the beginning of the video, the text tells you that a secret pheromone-harvesting ritual is taking place. Pheromones are present during sex. Now...what do you think they injected her with if she is labeled "Pheromone Doe" at the end of the video? Now, you can guess what was coming from all ...
It made perfect sense to me. Katy is singing about allowing someone to inflict themselves on her, to have a closer relationship. She's speaking of a woman who would do anything for the man she loves. And Kanye is singing about how great he perceives himself to be.