Male/futa futa/futa also works. And it will be left to the mods. But i dont think anyone will make one.
There exist a workaround for it. You just need to change 1 thing in the save file.
https://jsoneditoronline.org/# go to this site. Put the save file there. Then go to characters/search for your char hid/statlist/statlist (you see it right i put it there 2 times)/agreed_to_marry (check this) after that save the save file to disk put it back to the save folder delete .json and you should be able to marry the character you wanted.