Child custody in world where 3 partners required for reproduction [closed]

Question

Imagine a world with intelligent beings [intelligence equal to human beings]. In general things are like here on Earth, except there are 3 partners required for reproduction [e.g. one sex with the usual stick-like appendage, one sex with the usual receptacle/cavity, and then a third sex with e.g. a hoop appendage that must be between the stick-like appendage and the receptacle].

Say that all the usual reasons for having a child are still valid: parents want a kid to experience youth/growth/learning, want to mold a young mind in their image, want a financial heir, want someone to take care of them when old; or accidental/unplanned birth; or rape; or uniting family lines for legal/financial/power reasons; etc.

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My question is how does this 3 parents for reproduction arrangement affect the legal rules and rituals of child custody? (For sex A, B, C, there can be 4 divorce states: 3 ways to have 2 "remain married" while one separates, and 1 way for all 3 to separate)

Also, how will the legality change when there are N such partners, with N>3?

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*Also, I know someone might say that humans now are in some sense a "3 or more parent species" for some of the following reasons: 1) surrogate mothers 2) the mitochondrial genome is separate and traces the maternal lineage etc. 3) genetic engineering introduces genetic changes that potentially neither biological parent has...

But the 3 or N parent species I'm talking about has equal contributions of genetic material/responsibility, etc.

Answer 1

Does the species have any gender preferences for raising the children?

In the case of humans it is the female, but your species likely will have its own customs for gender preferences. It is possible that one gender does not have equal rights even in the eyes of the law thus get the least preference in the event of a divorce.

Divorce Mechanics

This is a tough one and depends heavily on how your species defines the contractual aspects of marriage. I recommend looking at how partnerships are ended in businesses when there are three or more owners involved. I found an article called The End of a Business Partnership which covers how to properly end such a relationship (and even compares it to a divorce at one point). Here is one of the main items from the article:

The Buyout

In the event that a partner wants to leave the partnership, there are a number of approaches that can be used. One of these is for the exiting partner to have his or her equity position acquired by the other partner or partners.

This can be done with a fourth person taking over the responsibilities of the person leaving the marriage, or the other two make some kind of arrangement to compensate the one leaving in order for the two staying to keep everything.