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 Square Mars
You may experience a high degree of sexual tension. Your partner stimulates a combative response in you whenever you feel that your emotional needs are not being met. Your moods stir up unresolved controversies, rivalries, and competitive feelings between yourself and your romantic partner. When the Moon person is square the Mars person, your relationship will often seem stormy and volatile until you can work out old issues between you. You argue, you make up. Eventually you work everything out or combativeness will become just another part of your relationship. This can be a very difficult emotional experience when there are children involved.