autochronocoitus
The act of travelling through time and copulating with oneself; Intercourse with a chronologically distinct iteration of oneself.
Doc longed for a simpler time, when people didn't lock their front doors. It's much easier to sneak in and molest children when the doors aren't locked. After inventing the time machine, he travelled back in time and molested many children. Some believe Doc unwittingly commited autochronocoitus, which lead to his pedophilia.