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 Inconjunct Venus
Your desires are not in syncopation with your partners romantic rhythms or sexuality. Acts which you find sexually pleasurable are unfamiliar to or outside the experience of your partner. You are both very attracted to each other but have different approaches to your sexual expression. When the Mars person is inconjunct the Venus person, you love life tends to be mutually frustrating and unromantic. they aren't turned on by your timing or technique. There is a learning curve to discover new mutual grounds for sexuality and sensation, but you will find yourself making constant adjustments to accommodate your romantic partners viewpoints.