My spouse has cyber affair with another man

Good morning. since past few months, I am in great mental distress. Initially I found my wife was chatting to some one on WhatsApp during April 2018. There were few sexually explicit materials which popped up in chat screen. But did not have had access to the phone as it was in possession of my wife. When I casually asked her what was that, she told it is a girls group chat. I trusted her and did not asked any question. It continued and I never had any doubt. one fine morning on November 2018, I woke up from bed and suddenly god knows what happened, I took her cell phone and started looking at that chat room to find out what is happening. I got shattered as I see that she was sexting with another guy. I saw his male genital pictures and her genital and breast pics being shared with each other. They were talking what would they do if they meet. Same morning I confronted her. Initially she did not agree to me. But when I told that I saw everything, then she told she wont do it again. She erased he phone number from her mobile. After that I used to keep watch but never found anything. To my worse, she was still continuing sex chat with the person and was deleting chat every time. In December, I went to my native to meet with my family. Her family (me and my spouse stay in Bangalore) also stays nearby so she went there to visit. after few weeks I came back alone. I was sitting in my laptop and was trying to open an webpage. on URL area, suggestion was coming like web.whatsapp and I accidentally opened it. To my surprise, my wives WhatsApp was mirrored there (go knows why she mirrored it but she did it and it was good). Now I see sexually explicit message exchange again started with same person on whats app. That person maintains another number which I got from another chat in WhatsApp as he mentioned there his WhatsApp number. Now I have screen shots of wwhats app with me for all her chats. bother mobile numbers of the guy. It is still continuing. I gave her 2nd chance to save marriage. But she is again doing it. please suggest what should I do? We do not have any child still now.