1. Changes predictable behavior
If you have been with someone a while, you can start to tell that they have certain patterns and behaviors that they regularly follow. When you notice that they are changing a lot of their predictable everyday behaviors, it is often the first sign that he is cheating on you. Be sure you ask for an explanation to make sure that they just didn’t find a more efficient way of conducting their tasks each day. You want to make sure before you start throwing out accusations.