I would start off by saying that one must know the important differences between love and lust. So many people in the heat of a new and exciting relationship fall pray to lust. This almost always insures a downward spiral to any relationship.
If you can take time to know someone, spend quality time with them in the same way you would a best friend; and if you find you enjoy each other company without sex, it could be love.
That is not to say all sex destroys any chance for love in a relationship, however, it can blur the truth of how real a relationship is.