Peccadillo: (noun) a small sin or a trifling fault
In a sentence:
GM: Get your things together and leave immediately before I call the police.
Cleaner: But it was only a peccadillo, please have mercy, I have a family to feed.
GM: Peccadillo or no peccadillo, you have shattered my trust in you and when that happens I turn my back.
Cleaner: I only took one pillow chocolate.
GM: So what? If I get caught stealing one Rolls Royce, does the car dealer let me off because I didn't take every one in his showroom? Be gone!