Im going to be speaking from my "PERSONAL EXPERIENCE" so not all the information may be entirely accurate... Then again this is all very biased, wouldn't you agree? I was in a 2 year relationship and around the middle of our relationship I notice several things about my significant other that led me to the conclusion that she was unfaithful to our love.
1. She will always snap when you ask her the simplest questions.
(example) Where are you going to eat?
Who were you going to the mall with?
How was your day at school?
AND EVEN SMALLER QUESTIONS... I feel that if your woman is unfaithful she will look for any reason to start an argument and use it as an excuse not to be around/talk to you so they can spend more time with there secret lover.
2. She will constantly lie and they will be most noticeable. Don't even try confronting her about this because that will just fuel the first TIP I stated above.
3. She will start buying sexier/flamboyant clothing and trying to look good. If your lady is already very classy and has a great fashion sense then this behavior is normal. but if she is very plain and dull then this is a tall tale sign that something is going on.
4. She has a new friend that she doesn't want to relinquish any general information about. He will be a ghost to you and your woman will find alot of her time spent with him.
5. Shes constantly guarding her phone when ever shes at home with you making sure you dont see it. she will be texting more often an paying more attention to her cellular device then you yourself.
6. She will become very irritated with you and start blaming you for many things and knocking down yourself esteem. she will become more angrier, less affectionate, and overall generally aloof.
7. She will and I cannot stress this enough!!!! LOSE HER SEXUAL APPETITE FOR YOU. she will try to blame on on fatigue and stress and a myriad of other things but you know your woman better then I do. If shes not getting sexually satisfied from you then shes getting it elsewhere.
Bottom line is if these signs appear in your relationship then you probably should confront her, its now or never. be strong my male counterparts