Moon in 12th House synastry – a strong emotionally-intuitive connection is gradually established due to excellent mutual understanding at the subconscious level. The partner’s mood and feelings are foreseen in advance.
If the Moon behaves negatively, or the general nature of the comparison is unfavorable, destructive tendencies, deception, and indecision of partners violate the integrity of the synastry.
In a positive scenario, the formation of business relationships is possible. The “lunar” personality very skillfully stimulates the deep roots of the subconscious of the Twelfth House person, however, the positivity or negativity of the consequences of this stimulation can only be determined by careful study of the whole natal chart.
from F. Sakoyan, L. Ecker
Moon in 12th House Synastry Explained
I awoke in the Midsummer not to call night, in the white and the walk of the morning:
The moon, dwindled and thinned to the fringe of a finger-nail held to the candle,
Or paring of paradisaical fruit, lovely in waning but lustreless…
Gerard Manley Hopkins — “Moonrise“
Moon in 12th House synastry is an aspect of deep relationships that can either immerse you and your partner in hell or elevate to paradise. Here, your general level of human culture and attitudes towards each other are vitally important.
If the wife’s Moon falls into the 12th House of her husband, both can sincerely believe that his main life task is to serve her as the mother of his children and the mistress of the House. There is nothing wrong with this per se: the point here is not so much that the wife’s selfishness can exceed reasonable limits. The main problem is her substitution of your ideal religious image, that is, God in the feminine form. Serving God has its own purpose, and replacing God, even subconsciously, with a mortal woman and her everyday problems is sacrilege and a karmic punishment for this can be very severe.
The meaning of Moon in Twelfth House synastry is that the partners should 1) see the karmic knots and unresolved problems coming from the previous lives, and 2) try to soften them on the external material of daily toils and mutual help. Speaking in the language of psychology, this aspect means the activation of internal problems, often associated with a sense of irrational guilt and anxiety and located deep in the subconscious.
A Moon in 12th House synastry partner can become your psychoanalyst, a psychiatrist, and even a spiritual teacher; but for this, you must show spiritual subtlety and complete altruism, which you can not practice right away since the temptation to lie to each other will accompany your relationship for a very long time.
from A. Podvodny