Mars/Neptune contacts in the birth chart produce one thing above all else... steam. These people are attractive in the old Hollywood way, even glamorous. Many, many male stars have had this aspect in their birth chart. Mars is the planet of sexuality, energy, drive, ambition and courage, and originally rules the 1st house. Mars is very concrete and straightforward. Neptune is decidedly different. Ruling the 12th house of spirituality, the unconscious, hidden things, the higher realm and our own undoing, this romantic planet is illusory in nature. Neptune is characterized by water. Mars is characterized by fire. Fire and water make steam.
A certain aura surrounds these people that makes the rest of us NOTICE. Often the women with this contact will have a glow about them that is difficult to pin down as either ethereal, sexy,dangerous, sexually innocent or all of the above. The men with Mars/Neptune contacts in the birth chart are downright sexy. These men have that dreamy, untamed sexual energy that traditionally characterizes the "bad boy." He is that guy who cruises off into the sunset on his motorcycle and as you watch him romantically disappear over the horizon (often as he gives you the finger as he does another woman while riding said motorcycle) you actually wish he would come back. Such is the power of the Mars/Neptune steam.
Childhood is difficult for individuals with these contacts due to the fact that a concrete idea of who they are eludes them. Often, it takes into the mid thirties or beyond to develop a real sense of self. Lying is a side effect of Mars/Neptune because it protects the sensitive ego and provides a way to try on different personas; for acting is a gift to these people. Neptune erodes what it touches and has few boundaries. Mars traditionally rules the first house. We can look at this contact as a first house/ 12th house issue. The 1st house blending with the 12th house is much like the body merging with the spirit. If the ascendant ruler is one of these planets, the energy will be all the more apparent. The ego is largely found in the 1st house, with Mars and with the Sun. Mars in contact with Neptune makes one prone to to a boundary less ego. Developing a real sense of core values, self respect and integrity is a life long struggle for Mars/Neptune people. The are ultra sensitive with the planet of sensitivity having conversation with the planet ruling the self. Lying to protect their feelings, living in a fantasy world to protect their illusions, holding out for that perfect other, and sexual addiction are oh so indicative of these two entities mixing.
Sex in it's rawest form is Mars. Sex in it's most idealized form is Neptune. When these two meet, we see a sexual idealist. Idealism in any form sets one up for disappointment and unfortunately, disappointment is a theme for Mars/ Neptune people. Mars shoots as high as he can and does not consider the consequences. Neptune shoots as far as he can and chooses not to think about the consequences. Neptune is basically addiction and Mars is where we put our energy. Mars/Neptune contacts can often result in fantasy addiction. Sex is the chosen outlet for fantasy and is the go-to balm for someone who's body and sexual energy (1st house) wishes to reside in the house of hidden bed pleasures (12th house). Achieving an ecstatic sexual state, sacred sex, tantric sex, these are the interests of the Mars/Neptune person. When not in pursuit of these things, their drive and ambition can suffer. Ambition is not something these people have a lot of outside of sexual fantasy fulfillment and the harsh realities of paying the bills, climbing the ladder, and providing can literally depress them.
Mars/Neptune people have the hardest time knuckling down. If they can learn to do it, if they can put their desire nature aside and work diligently to make something really materialize in the world, if they can see their ambition yielding fruit, this will go a long way to solving the issues of their eroded self esteem. Accomplishment is what these sexy people need the most.