My top pick for tips on how to catch cheating is this book by Sarah Paul

Why Do Married Men Cheat? - No Simple Answers

You get the chock of your life to return home from work to find your husband in bed with another woman. This scenario is often the way many women find out their husbands are cheating on them. It could also be a man that is in your bed with your husband and you are shocked to discover that your husband has been secretly gay all these years. Whether it is a gay or heterosexual marriage, you will look for answers to why do married men cheat. You will find that answering this question is not easy because there are so many factors involved.

Many married men cheat because the opportunity is there and they think they won’t get caught. Men who travel for business, for example, have the perfect opportunity to pick up a woman in the hotel bar and the wife waiting at home will never have any inkling of the one-night stand. It could also be a woman he meets at the gym who just want to have a fun time together. He still loves you, but is looking for something different and possible engage in sexual activities that he would never ask of you or figure you won’t want to engage in.

For some men, cheating on their wives makes then feel big and important in their own minds. It boosts their ego that they have what women want and can easily pick up women. They are simply adding names to their lists to see how many women they can say they have had. On times, they just want to prove that women still find them attractive and he enjoys the thrill of the chase. The excitement of sneaking around and not getting caught also adds to his ego when he thinks that he won’t get caught.

After a while all relationships start to wane and spouses tend to grow apart. If your spouse feels that you are neglecting him or don’t want to spend time with him anymore, he may start to look elsewhere to have his needs met. Maybe both of your interests have changed and he meets someone with whom he has more in common now than he does with you. While he may not engage in the affair with the aim of finding someone new on a permanent basis or is just looking for a little attention, it could grow into something more the longer it continues.

Many men fall out of love with their wives or their sex life has drastically decreased or become nonexistent. He will then start looking for someone new to fulfill his needs and start enjoying life like he once did. This is not to say it is the wives fault when men cheat, but it just happens that way. While the discovery of the unfaithfulness may be what it takes to end the marriage, for all intents and purposes, it was over long before this and both of you just didn’t want to admit it.