Is this consider as Extra marital Affair or Affair?

I got married to hindu girl. I found that my wife is not a virgin on our first night. Thereafter I started spying on her. I came across some msgs are being exchanged between my wife and her ex boyfriend. He had refused to marry her but still she was contacting him until 1 month of our marriage. I also have call traces going to his number from her phone. They stopped contacting each other after a month. Infact they never met each other after our engagement. Later we had a very good time together and had a great understanding too for some years. At this point of time, we both are fighting for other issue she doesn't feel that I am supporting or standing or protecting her enough. So now she is asking for divorce. Is texting ex boyfriend considered as an extra marital affair ? Can I file for divorce saying she had an affair ? Specially if texts mention that if wife telling to him that she will divorce me (husband) and she shared our marriage pics to her boyfriend. She continued texting him for roughly one month of our marriage. Does this consider as illicit relationship? I also have proofs(nude and intimate photos) that these two were physically involved before marriage.