Even though you are only have a steady relationship with your girlfriend and not a marriage cheating in the relationship is similar to a marriage where trust; loyalty and caring for the other person's feelings are a must. Once the bond of trust has been broken it is difficult to get back. There is no need to cheat and it is never too early to be mature about a relationship when you know you are either bored in your relationship with your girlfriend and want to persue other young women and you should have been honest with her. You dug the hole so now you have to live in it. The grass on the other side of the fence is not always greener which simply means now that you have cheated you have quite possibly lost your girlfriend and she may never trust you again.