Dick Turpin was a notorious highwayman whose cry, on mugging his victims, was supposedly "stand and deliver!". The origin of the Dick Turpin is presumably related to the fact of "standing" in order to "deliver".
Wayne and Sharon were so overcome with passion that they couldn't wait to get back to his Cortina and instead went for a Dick Turpin in the first available shop doorway.
A man's natural and involuntary reaction to being liked by a chick who's, ugly, fat, both, or has some other quality that would make a relationship with her a terrible thing. When the dick switch is flipped, as the name suggests, the guy will start acting like a dick/asshole to try to get the ugo/fatty/both/other chick to stop liking him.
Here's a text conversation after the Dick Switch was flipped.
Fatty: So what's your favorite color?(:
Guy: Green I guess.
Fatty: NO WAY ME TOO!!!(:
Guy: I fucking hate green.
Fatty: Um..what do you think of Brooke? She's like my best friend. :)
Guy: I think she's an ugly whore.
Fatty:... :'(