Can I share iCloud storage plan with another person ?

i have a 50gb icloud and my partner has 200gb, both are full. If one of us upgrades to 2tb, can we add the other person to this storage?

What will happen about their existing paid icloud? Can they stop paying for it?

will their existing data just be instantly merged with the new 2tb account?

if they want to split way back to their own iCloud storage at some point? How will this work?

thanks

[Re-Titled By Moderator]