Relationships are about trust and communication, but over time that can erode away. You may start out loving one another but those feelings can fade over time. You get bored with each other and want to experience new things. This is why most affairs occur.
There are ways you can find out if you have a Cheating boyfriend. They are not exact or set in stone, but they can be fairly decent guidelines to help you determine whether or not your man is going to someone else for his needs.
1: If he comes home late this could be a sign he is cheating. Now obviously it is not if he comes home late once in a while. There are a lot of reasons he may be late, from working late to having to deal with traffic. This only becomes an issue if he does it consistently.
Another thing you can look for is what he does when he gets home. If he goes straight to the shower, this can be a tell tale sign he is having an affair. If he is cheating on you he will want to hide the evidence, which is why he goes straight to the shower. He will probably avoid you at all costs as he heads for the shower.
2: If your romantic life has dwindled out, this can be another sign. It is not concrete evidence that he is cheating, as there can be other reasons why your love life is suffering. If this is the only sign you recognize you may want to simply talk with him about it as there is probably another reason why this is happening.
3: If he makes excuses for not spending time with you or generally just avoids you. If he is having an affair he will want to spend time with that person over you. So if he always comes up with an excuse when you try to do something with him, this can be a pretty big red flag.
Something you should keep in mind if you suspect you have a Cheating boyfriend is to play dumb. You can not prove anything if he is trying to hide it, so to catch him you need to be smarter then he is. If you pretend to be clueless and not suspicious at all, he will lower his guard.
You can lull him into a false sense of security by doing this, he will think he is some sly devil who is getting off scott free but in reality he is falling right into your trap. Eventually he will make a mistake, leaving a certain text message on his phone or allowing you to answer a call from his mistress.
Once you get the evidence you need you can confront him on it and take the course of action you deem appropriate. Whether you dump him or give him another chance is up to you. Just keep in mind that not all men cheat, and you would not want to wrongly accuse your boyfriend of being a cheater. So make sure you get solid evidence before making a move, otherwise it might be you who ruins your relationship.