Well if Lilith is the dark moon then it expresses itself though the house it's located in. Hidden depths and the darker sides of our nature would thus be expressed through the 7th House with Lilith there, however everything placement can be managed it just takes awareness and willingness.With Lilith in the 7th (my own natal placement) There is a conflict between our desire to commit to someone and remain independent. Lessons of course need to be learned.
Black Moon Lilith in the 7th
"Super-charged relationships and quest for perfection. The Black Moon relates to the deepest and most hidden parts of the psyche; the 7th house relates to close relationships. This can make the native project extremely high emotional charges onto partners and close friends. Personal attractions (and repulsions) can be exceptionally intense. Relationships can thus bring profound healing and/or an exacerbation of the deepest psychological wounds. This position is an invitation for the native to take a close look at whether they do project violent emotions onto the people with whom they are closely associated.
Black Moon-Lilith carries a profound longing for the absolute. Transposed to relationships this means you are likely to have high expectations of your partners, and thus be mortally disappointed when you realize they are not perfect like God. Withdrawing from relationships in such times of crisis can be a grave mistake, as these crises are often self-engineered to reveal profound aspects of yourself and allow resolution of your deeper conflicts, and healing.
Black Moon in the 7th is also a factor to attract people of great independence and originality to you, people with the qualities of Lilith: full-on passions and emotions, rebellious nature, dislike of patriarchal establishment and a need for absolute perfection." http://lilith.tribe.net/thread/a8f93941-6d00-4ca9-93d1-9da000134c23