When I confronted my husband I put on my sexiest nightgown, then I walked into the bedroom where he was watching tv and told him I knew the truth about him and his GF and he could stop lying to me. I went on and he sat there pretty quietly, still lying and clinging to his story. But I was proud of myself for standing up to him and saying what I had to say.
For us, it didn't get better right away. I shared my truth with lots of people. Not saying it's the thing to do. Just saying that's what I did. My kids were old enough to speak their minds to their Dad, and of course, they were on my side. Things got much worse between us. Until they got so bad that we knew we had to do something or we would make the front page of the newspaper (not in a good way). That's when we agreed to go to Retrouvaille. And for us, that was the road back together.
Your experience won't be the same as anyone else's. There's no way to know how it will end up. You need to be happy with yourself however things go. If you don't confront and say something, his behavior will not change. Deep down most of these cheaters know they are doing wrong. Some will never admit it. Some will change because they don't like what they have become. But doing nothing will not change anything. If you want to see change, you will have to make change.