Will He Cheat When We Get Married? My Man Is S3x Chatting Other Women

I having been dating my man for almost a year, he treats me right and I love him. The other day I was with him he went to get something outside, I noticed his phone on the bed and decided to go through it. I don't snoop but I couldnt resist the temptation of knowing what goes on in his mind and social life. I got the shock of my life when I saw on his whasapp all the girls he tells I love you ,he has like 5 girls he professes love to.

The worse is one even sent him a pic of her vjayjay ater sex chatting. He came in and I approached him. He shrugged it off saying its only a chat and he has nothing to do with them, but just playing around. We are planning to settle down soonest but with all these am having double thoughts. Is it possible to sex chat with ladies and still not have anything to do with them? I don't know what to think anymore. I am confused and I need to make a decision as soon as possible.