Recently I found out my wife has been in quite inappropriate conversation with another man, i seen their chat pop up while using her laptop and the content of one message was out of order so i clicked to read further into this. It had been going on 3 months or so and very sexual chats and even some non revealing but teasing photos had been sent. He was leading most of it but recently she seemed to be enjoying it more and playing along (she sent the photos) he kept asking for more revealing photos and she was teasing along.
It took me a while but i eventually confronted her about my disgust and i tried to be reasonable and understanding and asked was something missing from our relationship. I had on many occasions felt we were missing something and a few times asked her and she kept saying all was fine. After talking to her about this she admitted she is a bit bored and the younger man made her feel good and it was flattering, she agreed it was inappropriate and promised me it would stop. A few weeks passed and all seemed great but i walked in one day of her taking a close up of her cleavage lying in bed. She quickly passed it off and denied it. She has moved all messaging to snapchat so no history is available and she guards her phone closely which was never really a thing before. I feel its still happening but don't know how to confront her again in case i come across as possessive and controlling as I'm sure she will accuse me of this. We have always been a very open and trusting couple and this leaves me heartbroken and i feel I've lost trust in her since this but I don't want to be watching over my shoulder the whole time.
I feel betrayed even though by the messages nothing has happened physically ( well at least not up to a few weeks ago) but i really tried to be understating to make things work and feel she played along and made me feel she would stop to save any further conversation as she has never been into having relationship chats. Is the snapchatting her workaround so I don't find out or am i being paranoid. Her job leaves her open to late nights away and he lives near her job and although I don't thinks anything has happened I'm fearful it can easily under the circumstances as its normal for her job to have her in late and different times each night. I think if it is still going on i will lose all trust and not want to be with her but we have kids and i adore them and i would lost without them. Any advice welcome and thanks in advance.