Degrees of Lying
Little white. Gray. Black. Fibs. Are there degrees of lying?
If she tells you that she is hanging with a girlfriend, but neglects to mention that a "guy" friend was there, is that a lie? is it ok? a mere oversight to be forgiven? But what if it was intentional non-disclosure. Maybe there is a history with that guy friend. One you don't approve of.
Suppose you are kicking it and she suddenly leaves, stating that she has to do xyz with her kid....but later you find out xyz never happened or only took 15 minutes and the rest of the night she was hanging out with the girls? Suppose she told a small lie, but it was a long running one- a year, two years, perhaps your whole relationship? If she had the chance to correct her lie or come clean should you still forgive it?
Now flip the table. Suppose you went to the strip club and didn't tell her. Maybe you just went and played poker and enjoyed a cigar but said you worked late because you didn't want to hear her bitching. Suppose you were hanging out at a party with an ex. Or going somewhere when you knew some hot piece was going to be in attendance. Would should be so forgiving to you?
I don't think relationships should be a game, going back and forth to get revenge, but I bet you would be sleeping on the couch for awhile not getting any if you did the same.
So be upfront. Tell her you watch porn, read Playboy, play cards, drink rum smoke cigars... what ever your vice is lay it on the line. Because then when she lies to you, there is nothing to hold against you. You keep your balls and make the decision to keep believing the lies or ending it right there.