Repercussions of a Time Traveling Father

What if Harry Potter went back in time, fell in love with Lucius, and then was forced to return to the present? How do you go grow up and go to school with the boy who will one day be your father? Not beta read. See notes for a more detailed summary. Cross-posted to AO3. Warning: absent parent (Harry Potter); Lucius and Narcissa are good parents. Rating to be safe.