Pleading with the bad guys

I understand that it's perfectly human for a good person to say 'no!', and 'stop it!', when the villain is hurting someone else. However, there are times when the dialogue makes me ask myself, wtf?

For example, in Back to the Future, in the scene where George comes onto Biff when he's trying to force himself on Lorraine, everything works well, except for the part when Biff gets Goerge in an armlock and puts a harmful amount of pressure on him in one very puzzling way.

Lorraine tells Biff 'you'll break his arm.' When George is nearly bending all the way to the ground in the shot after the next one of Marty Mcfly getting out of the car trunk, Lorraine told Biff 'you're going to break his arm.' Okay, a few seconds later, she tries to make him release his hold by jumping on him and grabbing his arms, but warning Biff that he's going to break George's arm is like asking a flea not to suck blood. It's going to, whether anyone likes it or not.

Did she really Bifff was going to listen to her and let George go, knowing what he was like?! Honestly?

I do remember that scene is the movie. I took the scene as a comical than serious.

I think everyone in the scene was afraid of biff, and marty really shouldn't infer with that incident. do because of time lines, and marty's existence.

all women will pledge that no one will help. when the woman does this act in a scene in the movie is stupid. because the writer and the director believe show up the male hero in the movie, will ruin the movie.

she actually defend her and beat biff, why would she need marty to rescue her?

So, there was comedy value in the scene? I kind of sensed this in the way Lorriane told Biff he was going to brek George's arm. Did the director want to add a black humor to it?

you might been only who saw any reference to " black humor " in that scene.

I look at a normal scene that was somewhat funny, because that a bully would have done to weak person like George. I would been disappoint in the movie, if biff didn't try steal lorriane from George.

if the black and white comedy movies in 50's, that scene would be pretty normal back then do see.