Maintaining a sense of security and control in your life is a priority of yours, as it is for most anyone. Everyone goes through emotional or physical traumas that lead to the need for greater security in the current life or in the next one; you're no different, and neither is your partner. You've both been subjected to emotionally upsetting or even physically impoverishing conditions, in past lives as well as in this one, that have led you to certain conclusions regarding your own, personal sense of security.
But while you have responded to these traumas by trying to establish external structures that give you a sense of control -- logic, for example, or hard work, or responsibility -- your partner may be more interested in transforming themselves from the inside out. This approach is quite different from yours, and when they tune in to you at a subtle level and begin to try to transform you as well, you'll feel those carefully erected structures in your life begin to crumble. Ultimately, this could be a very positive experience for you; you do need, after all, to progress within yourself to the point that you don't need any outside structure in order to feel secure. But your partner's methods for trying to teach you this lesson could prove to be too forceful for you to handle. You may experience your sexual connection with this person to be particularly compelling and yet troublesome, as they will ask you to connect with them more deeply than you're comfortable with. But sex is a wonderful venue in which to learn about losing control and making yourself vulnerable to your intimate partner. Testing yourself on this level can only be a positive experience in the end. Just remind yourself that you have everything you need inside you in order to protect yourself, but also to grow.