Perfect girlfriend but still want to experience things, should I break up?

There are several things to consider in a situation such as this. I have been in multiple relationships and have always felt a nagging feeling about this. She may be perfect, but do you feel like your relationship with her is right for you now? People have different perspectives on monogamy, especially at younger ages, and this is one factor to consider. Second, you may want to think about the reason behind those feelings. Are you feeling dissatisfied for any particular reason(physical or emotional?) I can't make this decision for you but you should definitely think carefully about your goals and ambitions when doing so.