Detective: What'd you do with the diamond rattlesnakes?
Suspect: What do you care? Are you going to arrest me for
blurring the lines?"
Detective: We're leaning towards murder.
Does "blur the lines" mean "not cooperate in criminal inverstigation"?
I couldn't even google it.
What does that idiom mean?
Also I want to know why the plural form "lines" instead of "line" is used here.