"Duckie does himself no favors here. By insisting on hanging around Andie at every possible opportunity, he’s only making himself look like an annoying little brother who thinks it’s funny to bother her at work by repeatedly setting off the alarm in order to get her attention, calling and leaving messages on her answering machine 20 times in a row (with less than a minute between calls), using studying with Andie as a way to try to force her into spending more time with him.
Later on, he graduates to increasingly unsettling, even creepy behavior, riding his bike back and forth in front of her house for hours – hundreds of times by his own estimation – then following her all the way to Chinatown just to stand out on the street-corner and stare up at the window of Iona’s apartment. What he intends to accomplish by doing this is hard to say; call her to the window via telepathy where she will see him, realize just how hurt he is and be swept up in waves of sympathy that lead to sloppy makeouts in the back of her car?
The film wants us to feel sorry for Duckie, who, in the narrative of the film, is losing both his best friend and the woman he’s been in love with for most of his life.
In the real world, this is the sort of behavior that ends with a judge telling you that you now have to keep at least 500 yards away from someone or they get to call the cops."