First off, I would like to start by saying that that there is a huge difference between dating and being in a relationship. If you are dating someone, you are not necessarily in a monogamous situation and you should not expect the other person involved in the situation to be monogamous. When you are actually "IN A RELATIONSHIP" then you should be exclusive with that one person and ONLY that one person. There is a huge misconception of people who are just dating or people who are actually in a relationship. If you want to see numerous people at one time, then date. If you want to be with that one certain boy/girl all the time then you should make things exclusive. All it takes is a simple discussion.