> So with everyone getting free money, including the children, there is no need for a father to take care of the family when he decides to diforce, right?
It certainly would mitigate the social harms caused by deadbeat abandoning parents, but since neither child support nor alimony are currently limited to the amount necessary to provide basic survival necessities, a UBI mature enough to provide basic necessities would not seem to be a basis for eliminating existing child support and alimony provisions.
Obviously, even with existing formulas, the fact that more of the family's income wouldn't be leaving with the prime breadwinner would reduce the amount of support and alimony orders.
> So marriage will no longer be a bond forever
Marriage, in the US, is only a "bond forever" now to the extent that the parties decide to make it one; divorce is readily available, and frequently chosen.