They tend to talk alot/give a lot of details. I heard they when someone's lying they'll look to the left vs. Looking to the right when they're trying to remember something (i'm not 100% sure about that though).
maybe if they talk about it all the time, or they look too happy about it like they are bragging and kind of smirking behind your back because they think you're so stupid to ever figure it out.
like my guy for example, he talks about his ex so much like they had the best life in the whole world being sluts and whores, then when I get mad and say... OK it was so good then why aren't you still with her. If you brag about it so much and are so happy talking about it then why don't you go be with her.
Then he starts telling the truth, or who knows if that's the truth. Once a liar always a liar. 100% of what he says has to be taken with a grain of salt. In other words everything my guy says, I don't believe in it one bit. He's a total complete LIAR. He starts saying she cheated on him, never paid attention to him, they didn't have that much sex, sex was only 1 position... what BS. What happened to we had sex 10 times a day in multiple positions with multiple foreplays with lots and lots of food? Oh you lied? She only was on the on top position raping you? Oh she never paid attention to you and ignored you 100% of the time? Oh... I see... What is the truth. Everything is BS. Everyone lies... if you find someone like me who cannot lie for the life of her, and I really am the suckiest person at lying... then you're lucky.
Also I at first am really gullible adn believe everything everyone says. That shows to you that a person would NEVER lie because she wants to be taken seriously all the time.
If a person always jokes with you, you should sort of think she's still joking with you. Like the boy who called wolf. IF she said she was dying 1000000000000000000000000000000 times and then she said it again, you'd know she was lying because she lied the other 10000000000000000000000000000000000000000000000 times.