Sorry, but this implies the collapse of the moral foundation started with the gay marriage bit.
Which is of course nonsense. It started with the general acceptance of premarital sex. The second brick to go was easy divorce.
Once you abandon the ideal of sex limited to marriage, there is no logical stopping point short of the "anything goes" for consenting adults point we're at now.
I think we'll stick with the consensual part, but I expect the "adults" part to start eroding soon.
The problem is that most people were more than happy to accept the removal of the first brick, since it provided justification for something most of us are inclined to do anyway, and now we're on the slippery slope and accelerating towards the bottom. To scramble metaphors.
It’s also important to notice the approval of general single parenting too. It is part of the collapse.