It is never an easy decision whether to confront your wife about her cheating or hope she'll come to you on her own. It's even harder if you simply suspect that she is cheating but lack the proof.
The first thing you need to do in this situation is find out for sure. Not knowing but suspecting is the hardest part. Remember, no matter how strong your suspicions may be, there could be something completely innocent going on. Until you know for sure it would not be wise to confront your wife about her cheating.
Once you have the proof you have a few decisions to face. There is no right or wrong answer to this question that works for everyone. You will have to decide what your next move needs to be.
For the most part, men aren't all that good at sharing things that are most important to them. You probably aren't the rare exception to this rule and there is no reason you should be. The question for you isn't if you should confront your wife about her cheating but how should you confront your wife about her cheating.
Step One. Offer your wife compassion and understanding rather than anger and accusation. You may be hurt and filled with rage but if you confront her with these emotions she is going to do one of three things. She will retreat into herself and pull away from your relationship, she will go on the offensive and release all the pent up hurt and anger she perceives in your relationship, or she will decide it's easier to walk away than to try to save your marriage.
Step Two. Ask the questions you need to hear answers to. Again, work as hard as you can to keep the anger out of your voice. It's one thing to let her know that you are hurt by this (you both need her to know that her actions hurt you). It's something else entirely to pour more poison into the process than is already there.
Step Three. Decide where you want to go from here and what your next move should be. Once the confrontation has been made and all of your questions answered you will both have some major decisions to make. You can either work together to try to save your marriage or you can go your separate ways. Your marriage can't keep going like it has been.