On the surface it seems pretty clear cut. When you see yourself committing adultery with someone else, then you are quick to worry that you have latent desires for another woman. You worry that your love for your wife or husband is slipping and that you need to do something to spice up your relationship before it goes kaput. Just because you have a dream about having sex with someone else does not mean that you are unfaithful. The entire act was committed purely mentally and involuntarily. Do not worry that you are a bad person; in fact sometimes the definition can even be fairly benign.
When you commit adultery in your dreams this could simply mean that you are bored. It does not have to mean that you are bored with your significant other or that you are thinking of being with someone else, it could just mean that you are bored in general, and here is why. Often times our dreams are not able to spell out for us exactly how we are feeling in plain language. Our subconscious tells our conscious about our feelings through use of symbols. When we feel bored with something, our mind uses a symbol for boredom.
However, our minds cannot just use any symbol for boredom, especially if the feeling is terribly pronounced. We want to get our own attention. Therefore our brains latch onto one of the most powerful symbols for boredom, which is adultery. We culturally perceive adultery as a form of boredom with your relationship. Because you are bored of having sex with your significant other or because you are bored of your main relationship, you seek the comfort of others. Since we see this as boredom, whenever we need a strong and eye opening symbol, this is the kind of thing our minds resort to in order to deliver the message full force.
You just need something new in your life. Try going out for walks, or starting some other kind of recreational routine. The main way to make yourself less prone to having dreams about sleeping around is to go out and change something about the way that you normally operate. You are clearly not content with the normal goings on of your life or you would not be experiencing these inadvertent cries for help in your dreams. Instead of being content with your old routine, start a new one, or incorporate something new into your already existing routine. Try starting a hobby, and you will be surprised how quickly your life begins to turn around.
Of course, your dreams could also mean exactly what they seem to mean and it could be representative of a latent desire to be with someone other than your loved one. If this is the case you might want to really evaluate your true feelings for the person that you are with, to see how truly in love with them you actually are.