How do you tell if your wife cheats?

here is how you tell when she calls and tells a huge lie that is unbelievable , goes out for untold hours , doesn't spend much time with you and she spends more time going out of the house I am a girl but you can either go to cheaters.com or call cheaters what they do is they follow her around with a hidden camera and if she is having an afair or something they will let you know and show you on camera and then you get to confront her on TV