I initially thought that you were saying that if it wasn't love at first sight - like within the first 90 seconds, then you need to dump them. Of course, that isn't realistic. But I do agree that if what you want is to get married, then you should place some time limit on the amount of time that you will stay exclusive with them. That can vary. But I think what needs to be emphasized is that you should NOT spend your 20's is a series of 3-5 year long term relationships (which is what most people do) until your expiration date wears out. Then you marry out of desperation or you force some guy with an ultimatum of marry or quit. You could have probably figured they weren't for the long haul a lot sooner than that. But if you don't want to get married, then you can do whatever you want and you shouldn't consider the time spent as "wasted". That isn't wasted time, it is time spent making memories and enjoying your life. The reward is the experience itself and shouldn't ultimately get tied to something like getting married. I am always troubled by people saying their time has been "wasted". If it was being wasted, then you should be spending time with them period. Truth be told, marriages don't last either. So if you think your goal is marriage to provide some stability, that isn't realistic either.