|The UnHoly Trinity|
There is no scriptural or ecclesiological reference that can justify any expression of two popes.
Let's be clear, if both these men think that they are Pope, then neither one of them is Pope. There is not shared papacy. There is no shared Petrine Office. There is no spiritual pope and practical pope.
If they believe they are both exercising some joint form of the Petrine Ministry then they are both deluded and liars and even malefactors and will be judged by God for what they have done!
On a personal level, I've had about enough of both of them and their innovations and what I do know is this, this is not from God, though He is clearly permitting it.