I read about it in a book.
A magical partnership is a kind of partnership where the partners agree to learn and practice magick together. They can cast spells, engage in rituals, as well as teach and learn from each other, among other things. A magical partnership is not new. Take, for example, the partnership between the famous occultists, John Dee and Edward Kelley. There are, of course, many other unknown magickal partnerships that have been formed in the world that paved a way to a truly magickal experience and mystery. Even in the old grimoire of the Alexandrian Book of Shadows, it also suggests some form of magickal partnership between a male and female practitioners.