Today’s expression “jemandem auf die Pelle rücken” is somewhat colloquial, but also often used when a person is huffish or annoyed. Let’s break it down.
die Pelle is colloquial for die Haut = (human) skin but can also mean sausage casing = die (Wurst)pelle, and the verb rücken = to move or to advance.
Hence the literal translation of “jemandem auf die Pelle rücken” means to advance onto someone’s skin. Again, a very figurative German expression which is best translated by ‘to pester someone’.
As you might know, Germans prefer to have a zone of personal space around them, meaning we don’t like it when people come too close, for example when standing in line or being crammed in a bus or train. If someone is getting too close, you might therefore say
“Jetzt rücken Sie mir nicht so auf die Pelle!” – Stop pestering me! or Stop invading my personal space.
Remember, this is colloquial German, so be cautious when you use this expression in a public place.
The expression is also often used when the police or other law enforcement agencies are closing in on a target.
For example in a sentence like “Der Staatsanwalt wird ihm wohl auf die Pelle rücken.” – The prosecutor is probably going to question him.