Well, if you have Venus in Gemini now, it's just for this life. But I understand what you are trying to say (I also have Venus in Gemini)! You may very likely have two big "loves of your life" or "soulmates." Just hope it's not at the same time--very confusing and quite awkward, there are stories I could tell! I was blessed with two great loves, one when very young, and the man I married for 34 years (whom I met while seeing the first one).
You are right about the nodes, the South one is about Past lives, and the North one is about this life. They are usually opposite each other in the zodiac sign, but not 100% of the time. We are all supposed to be trying to balance our karma from past lives using the direction or guide of where the North node is in this life. So with the S. node in Leo, in other lives, you were strong, very devoted in love, very protective, and romantic. You showed your heart on your sleeve, and were dramatic. Your North node is probably in Aquarius for this life. So you are a bit aloof in love and are attracted to others on an intellectual level at first.
That's true of the Venus in Gemini too. So, with two air signs, Gemini and Aquarius, you always were attracted mentally to others. Gemini wants to talk a relationship to death or at least will air all the problems, and it's good to get them out in the open. It's fun and light-hearted, even if other planets are in signs that make you more serious. Aquarius loves, but needs to kept interested, and needs a bit more freedom.
This may have been confusing since I talked about Venus and Nodes, two different, but sort of related in love and past life astrology ideas... If I didn't answer this so it made sense (very possible) you can go to my Profile page and email me through Hubpages.com, and we can discuss it more personally. That's open to anyone with a question, by the way.