This relationship may show you a side of yourself you weren't aware existed. Getting involved with this person will tap into an old and very deep-rooted vein of power and vulnerability within you. Your partner will set off your internal urge to control them and the relationship, and you'll find yourself becoming jealous, possessive -- maybe even behaving in ways you would never have expected of yourself.
This could turn out to be something of a difficult pairing, but not without potential for great transformation for you both. But to harness the benefits and minimize the more negative possibilities for this affair, you'll both have to do some work delving into your emotions -- you, especially, because you were the one who, in another lifetime, betrayed this person. Subconsciously, you remember that betrayal, and in this lifetime you may worry that they'll turn the tables on you -- that they'll pay you back for what you did to them so long ago. The first step, then, toward resolving this difficult and powerful karma between you will be to recognize that your past-life connections no longer have power over you. Once you can let go of your own fear that your partner will betray your trust, you can begin the work of facing your deepest, darkest emotions -- guilt, need, anger, possessiveness, desire -- and transforming yourself into a more trusting and supportive lover. You'll find that it's better to have a strong positive influence over your lover than to have a strong influence that hurts you both.