I think my girlfriend is cheating on me again

I am 23 and my girlfriend is 21. We have been dating each other for 8 years. During my school days, I used to cheat on her, but stopped after we finished schooling. She moved to another city for higher studies and, 6 years later, I found out that she was cheating on me with a guy in her neighbourhood.

I had a talk with her and she said she would not repeat it. A year later, I caught her cheating on me again, with the same guy. I gave her another chance though. I now think she is cheating on me again because her behaviour has changed. She lies to me. Whenever she goes out for some work, she either leaves her phone at home, puts it in flight mode or doesn't take my calls. When I ask her why she doesn't pick up, she gives me a new excuse every time. How will I know if she is cheating or not?

- Subir S

You don't really know, to be honest, because you're not in the same city as she is. Chances are she's not, because your long relationship with her ought to enable you to give her the benefit of doubt. Having said that, her past behaviour doesn't make it easy for you to trust her either, which is a serious problem considering how important the element of trust is in any healthy relationship. In the absence of evidence, all you can do it pit your word against hers, which isn't really helping your relationship in any way. I suggest you meet her in person, tell her why you feel the way you do, give her a chance to explain her behaviour and, if necessary, find a way to either trust her as you go forward or end this if either of you believes there is no future together. There's no point prolonging the inevitable simply because you have a history together. Without trust, this will only get worse.