Mars shows what a woman is attracted to in a man. Being with a man who is strong in her Mars element, or who makes close sextiles with her Mars, makes the relationship much easier, and increases sexual desire and compatibility. For a man, his Mars is part of his masculine nature, so it is best when his partner also relates well with this element.
Mars Square Venus
You are attracted to your partners gentleness, they to your assertive passion, but both of you approach sexual and romantic relationships in your own way. Passion may be expressed as friction, argumentativeness, and competition between your competing styles. When the first persons Mars is square to the second persons Venus, they are can be put off by disharmony but fired up by your amorous attentions. You may find this works better for dates than it does for domestic situations. Whenever the sexual fireworks die down, you can find each others presence unfulfilled.
Useful Mars Square Venus Crystals