Do not lie at work.
I am not appealing to morals here. Do not lie, because you suck at it.
How many lying classes have you taken? Yeah, thought so.
I haven't taken any lying classes, but I've taken a bunch of comedy classes. I learned to focus and identify microexpressions, delicate changes in tone and body language. I'm not the world's greatest lie detector, but I am better than someone with no training at all.
I can report that most of my colleagues are miserable at lying. People have VERY OBVIOUS tells. The slightly too long pause, the sudden change of pacing, the awkward change in tone... these signals are obvious to any trained comedian.
Acting is hard. That's why it is a job!
I know I'm not good at lying, so I don't bother. When I screw up, I take ownership and try to fix it. You'll get more respect for owning up than for covering up.