Maybe this comment by Maritha Pottenger can give you a clue:
You might seesaw back and forth in satisfying your urge to know MORE. You may inhibit your actions with a quest for perfection (or believe you can do anything). You might overdo or underdo the urge to go beyond known boundaries. You might experience extremes in terms of experiments or risk-taking. High expectations could influence your partnerships. Freedom issues affect your relationships. You are attracted to people who stimulate your mind or who are idealistic. Your partnership(s) will be strongly affected by ideals, values and beliefs. You seek a sense of growth and expansion in your associations. You are apt to be restless, creative and progressive in partnerships.
EXAMPLES: Brooke Shields, Henry C. Lodge, Albert Schweitzer, Upton Sinclair, Auguste Rodin, William Holden.
It takes a while to figure out what do you want from a relationship, since you have a deep need to learn something from your partner. That appears to be very hard to articulate, but it relates to becoming more familiar with your own emotions. The partner is supposed to help you with that. If not, you become disillusioned with a relationship and may decide that you suddenly want your freedom, possibly because you are not getting the blend of challenging erotic experiences along with stimulation of something deeper with in you. You question makes me think of Kate Winslet and her marriage issues,and I think her Chiron in 7th is the reason for that. The solution is possibly just to keep looking for that deeper bonding, and just keep on moving on if the relationship is not fulfilling.