Liars think very fast
When someone’s bad at lying, you usually can tell. They have a hard time responding to tricky questions, especially if there’s something serious involved. Any “ums” and “uhs” are instantly dead giveaways of a lie, a fact that constant liars are very aware of, so they trained themselves to think as fast as possible.
Liars are great at being on their toes when being caught with a lie: they’ll get out of a situation faster than you can blink. If you know someone who always seems to have all the right answers, it’s time to reconsider your relationship. This kind of person simply can’t be trusted.