There was a bizarre case of two elderly "gay" men in Pennsylvania who were trying to work out some kind of deal like this. One of them was in his 80s and his "partner" was in his late 60s. They wanted to be considered spouses for some kind of tax/inheritance purposes. Pennsylvania law didn't allow them to be married, so they tried to get around the law by having the 80+ year-old guy adopt the guy in his 60s.
A Pennsylvania court ruled that the older one couldn't legally adopt the younger one because the father of the younger one was still alive. So -- get this -- they got around that little problem by having the guy in his 60s adopt his older "partner."
If you're going to live in a freak-show, it might as well be an entertaining one.
There must be other creative ways around taxes/inheritance tax without using “adoption.”
For example: Why couldn’t one guy simply write the other guy into his will? Or why couldn’t they just add each other’s names to each other’s accounts and investments?
The givernmint has the standard for self determination and codified all relationships are based on some amorphous voodoo canon.