Theory Four:

Everybody Lies.
We all do it. Sometimes you do it to save someone from pain that you may cause them from telling the truth. Sometimes because you're ashamed or embarrassed. Sometimes because it is just flat out easier than telling the truth.
What makes it worse is when you yourself have a back for lying, you're really good at it and sometimes you do it just to see if you can, because then you start to think about how easily you can do it and if other people around you are also lying. It's like gossip, if you're talking about someone, who's to say they aren't talking about you. There is also the karma aspect if your a liar yourself. You find yourself thinking "Holy cow, karma is going to bite me in the ass for all the lies i have told". Then you just go mad wondering who is lying to you. Is it the guy you're laying in bed with, or your best friend, or a loved one keeping something from you for your own good? With todays society and everyone we interact with you have to figure at any given moment someone is keeping something from you or just straight lying through their teeth. There's the classics of the dating scene: I don't think I can handle a relationship right now, I don't want to be exclusive until I can be 100% in it for you, and my personal favorite (which I have used on more than one occasion) I just need some time to figure myself out. Now I'm not saying these are always lies, but considering I've spun that crap before they could easily be cop outs.
Thank you Panic! At the Disco, but no, liars do NOT turn me on.
Just some food for thought.