I used to think that Skyrim mods covered the full spectrum but I was wrong. Now you can follow your doppelganger around and, well, marry them. If you want.
PsykotikKrymes’ The Doppelganger Follower mod adds your character as a companion in Skyrim: Special Edition. They have the same face, same physical likeness, same spells, same…everything.
So, it’s one for the narcissists. On the plus side, not only will you have a lot in common with your sidekick, but you know they’ll be able to hold their own.
Check out the Nexus page for The Doppelganger Follower mod for installation instructions and more information.