Traditionally, Saturn transits and solar arc (SA) directions to the descendant signify marriage. The reasoning is that the descendant is the marriage partner, and Saturn signifies contractual commitment, thus the legal institution of marriage. But experience has shown time and again that very often Neptune’s transits or SA directed hits to the angles also coincide with marriage.
Take a look at this example, of a woman who got married just as transiting Neptune passed over her natal MC:
You can see in the monthly ephemeris for 1967 (positions of planets on the 1st of each month) that Neptune hovered right over the MC from June through October, culminating in the wedding:
The circumstance around this marriage (as discovered later) was rife with deception, which is of course a particularly Neptunian quality, and resulted in a divorce within a short time afterward. This doesn’t of course mean that all marriages that are solemnized during a Neptune transit over an angle will result in a divorce, or be cloaked in deception.
There’s a dictum in astrology that says nothing happens that’s not promised in the natal chart. In this case, there is a strong Venus-Pluto conjunction in the 7th house of the natal chart. Venus is relationship and the 7th house is the marriage partner, to which Pluto brings one or more of its qualities of intensity, power, betrayal, etc. So there was a propensity for any of these issues in the life, almost all of which played out almost to a T in the period between the marriage and the divorce.
Here’s another example, a woman whose marriage coincided with transiting Neptune in dramatic conjunction with her natal descendant:
Also, Venus and Jupiter are transiting the 7th house, having just crossed the descendant line. Since the 7th his the house of marriage, and three transiting planets are crowding it right by the descendant, you would be hard pressed to not think of a prospective marriage. Which is exactly what happened.
The odd twist in this story is the woman had not really wanted to marry, but only did so at the time to please her parents. There is a sense of craving in to pressure, and a certain quality of helplessness and passivity, which are Neptunian hallmarks–the relinquishing of the ego, and one’s own desire, in service of another individual or group. In yet another case I know of, a man who had for some time resisted the pressure from his parents to get married, gave a little ground, dithered for a year or two, and then finally threw in the towel. At the time of his marriage, transiting Neptune was right over his natal IC.
Many marriages carry a great sense of illusion, a grand dream, or an escape from loneliness. Or, the marriage turns out to not at all what was expected or promised. Such marriages are often accompanied by an unmistakable Neptunian influence.