Back to the Future 1 fanatics - Possible goof that I can't find anywhere?

Why does Lorraine start calling Michael J. Fox "Marty?" a href="http://www.geocities.com/lazymothersp/backtothefuture.htm" rel="nofollow"http://www.geocities.com/lazymothersp/ba…/a If you click this, about 2/3 of the way down the page you will see exactly what I am talking about. When she is talking to her girlfriends in the scene that Marty steals the skateboard, she clearly tells her friends that that's Calvin Klein, and that she is going to find out where he lives. Once she gets to Doc's lab, the first thing that she says is "Hi Marty" and refers to him as Marty for the rest of the film, yet IMDB and a few other websites don't point this out at all, and websites are pretty quick to point out goofs in this movie series. It hasn't even been brought up that it was mistakenly referred to as an error because she could have heard Doc calling him Marty when she was waiting outside Doc's lab, but that wouldn't even make sense because for the entire movie leading up to that point she has only known him as Calvin Klein and she never questioned what his name was. Not too mention the continuity issue it causes in the movie with how Marty gets his name. At the end of the movie, it's because they met Marty that George and Lorraine point out how much they like the name Marty, foreshadowing naming their kid Marty, but how did he get the name if they never met Marty before naming him... before he went back in time. Yes, I know that I like Back to the Future way too much and I read into this more than any human being possibly should, but I don't feel bad about it one bit :) Love this movie!