I have the belief that you should not lie to a person regardless of the way the truth may make them feel because the truth shows more respect. Being 2-faced is the same as lying. Lying insults the intelligence of whomever you are lying to. Also, a lie pretty much always gets figured out eventually. I guess you may not want to say the truth if the person has anger issues. Other than that I see no true reason for it.
I have to write this post because of something I have dealt with recently. I absolutely hate 2-faced people though.The ones that will be nice to your face and then say no limit of nasty things about you behind your back without even the slightest bit of conscience of the ugliness they portray in doing so. That whole saying “if you can’t say something nice, don’t say nothing at all” should be in display regardless of who you are talking to. However, if you must say the not nice something…then tell the person that is in issue you do not like them, possibly with the reason, and be done with it. Don’t keep talking about them.