bendrosimp
Harry Potter, 16 years old, war-hardened, magically overpowered, and utterly unsupervised thanks to a distracted Dumbledore, has a plan. A brilliant, terrible, insanely Gryffindor plan. After realizing he has access to time-turners, fertility rituals, and a bit too much knowledge about magical genetics, Harry decides to go back to 1899... and get Gellert Grindelwald pregnant with Albus Dumbledore's baby.
Because - and Harry says this with total sincerity -
"I wanna help my magical granddaddies heal through the power of co-parenting. Also I'm bored."