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 Conjunct Sun
A Mars conjunction Sun aspect indicates that you will have an active role in your partners goals, lending power and influence to what ever course they take, helping them face challenge and overcome obstacles. Powerful physical sexuality is indicated. When the Mars person is conjunct the Sun person, emphasis will be placed on your goals for self expression and your partner will encourage your efforts.