To be passionate about someone is to want to merge your individual worlds. We tend to be passionate about those we love. This can be identified by overwhelming thoughts, intense desires to be in the other's company, and share knowledge of one another. Specifically, we are talking about an intimate, long-term relationship. The bond you share feels like a protected invisible layer separating the two of you from the rest of the world. A partner is typically the primary consideration when thinking about someone who we are passionate about, but it can be anybody. It's up to you.