The Moon is the most important 'planet' in relationships. The Moon represents deep security needs, and it is difficult to be with with someone who does not offer us what our Moon needs. Positive Moon compatibility will show two people who feel "at home" with one another, and instinctively care for one another. It's like being family. That's why it's the most important planet in synastry. If you want to spend the rest of your life sleeping in the same bed as someone else, you obviously need to feel like family to one another.
Moon Opposition Jupiter
You have your own feelings and your natural approach to luck, optimism, freedom, relationships and romance, but you sense it isn't up to you anymore. You have to balance them with your romantic partners attitudes and viewpoints in order to have harmony in your domestic life and their approach to things is quite different from your own. When the Moon person is in opposition to the Jupiter person they feels that way about you. You were both attracted to each other because you each have something that the other needs. Learn to balance and you'll both expand your horizons.