Back to the Future would be slightly different in that universe. Marty fucks the shit out of his mom. Like…really goes to town, while Doc tries relentlessly to get him to stop sleeping with his mom so much. Because Doc knows, but can’t tell Marty because something something time rip too many actioms changed, blah blah blah somehow Marty sleeping with his mom made trump Biff president. And now we’re in the bad timeline.