Accusing you of being unclear/vague in your suspicion -- Note that if you tell an honest, innocent person something like "your story seems inconsistent and I'm worried you were doing something bad," she will elaborate on her story and attempt to alleviate your suspicion. On the other hand, if the woman knows she really was doing something bad, she will try to corner you into making arbitrarily specific accusations that she can legitimately deny while withholding an explanation of what really happened. This is a trap in multiple ways because it also forces you to seem desperate and jealous in the hope of getting the truth. If a woman does this to you, do not feel tempted to think of more specific accusations. Just sit quietly and watch her talk. Doing this will cause dread and she is quite likely to give in, become frantic, or contradict herself.

Randomly citing perceived problems with you or making "hypothetical" excuses for things that she denies -- She may say she doesn't feel like you value her or that you don't express your expectations clearly. She won't say she slept with that guy but what she is saying definitely sounds like an excuse for sleeping with him. If she's making excuses without admitting to the crime, she is trying to rationalize something that she has already done. Withholding the actual confession is just a form of damage control.

Asking why you care or why you can't just move on -- In most cases, people are very accepting of general curiosity. If you ask a random friend what he was doing last night, he will try to answer and probably won't stress out about your reason for asking. If a woman cares about you, she should theoretically be even more trusting and open with you than this random friend. If you ask a woman something and she instead gives some vague answer while questioning your motive for asking, she is guilty and trying to dodge the issue.

Saying she doesn't remember -- Watch out for this especially if alcohol is involved. No one is as forgetful as a lying woman. They don't really have the constant gaping holes in their memory that they say they do. They aren't that different from you. If someone claims to be this forgetful she is lying. This amnesia is often paired with the "why do you care so much" response. When she says "I don't remember" what she really means is "yes, I did it but I had special tingles so it doesn't count."

Revealing something concerning in an artificially casual/nonchalant way -- For example she might tell you a totally mundane story about how she had fun visiting her friend last night, then a couple days later she reveals some detail she left out like "lol I just got a text from this guy who tried to hit on me and my friend that night." Then you might ask why that guy has her number and suddenly she gets defensive and confused about why you are asking. This is the beginning of "trickle truth." The idea is that she tells you something small so that she can claim she tried to tell the truth but she presents it in a way that forces you either to accept it and seem passive, or to keep probing and seem desperate. In either case the lie will drag on and she will have crushed you and sucked out your soul before you have any chance of getting the whole truth. The appropriate response is to next immediately when she does anything that violates a boundary. Make sure you know what your boundaries are IN ADVANCE. Don't let her confuse you about your boundaries. She will try.