singlehandedly, the stupidest phrase i have ever heard. it is not funny when used to a student and it is not funny when used to a coworker. you are not witty, you are a dumbass.
first off, there is no way that you can in any way compare working hard to hardly working. how can you confuse the two? you can't.
second off, if you have in some way found a way to a management position and use this phrase, someone in your office is going to send you a big bag of poop.
thirdly, it is not a pick up line. a pick up line is, "hey baby, do you have any black in you? you want some?" this does not compare.
fitzgerald: hey sexy mama, working hard or hardly working?
helga: go fuck yourself.