In a past life, you two were closely related, like a child with its parent or other caretaker. Don't worry -- in this lifetime, that doesn't have to translate into some kind of nurturing relationship that never gets romantic! Instead, it means that you share a really nice connection and you really take good care of each other.
You know the kind of friend who always looks out for you, who always wants to know how you are and to help out if you're feeling blue, or stressed out or anything else that's less than wonderful? The kind of friend who you know will help you move, or who doesn't hesitate to take you to the airport at six in the morning. That's the kind of relationship you two have, only you're more than friends. What could be better? You look out for each other and give each other the sense that you've got each other's backs. Depending on other aspects between you, this could be the kind of relationship that lasts long-term, and could easily lead to a marriage or commitment. Even if you're destined to have just a short-term affair, there's a good chance that you stay friends afterward.