What should I do about my wandering eyes??

Okay, I have been seeing a guy for about a year and a half. He is my first boyfriend and my first love, and we are very close. However, in recent months I've begun to develop a wandering eye, and I wonder when is the right time to break off my current relationship and play the field a bit? We don't fight, and we don't have any major problems, so I wonder if breaking up to see other people would be really premature?Another thing is that while I'm pretty active and involved in extra-circulars (we're in college), my boyfriend is something of a homebody, and wouldn't have a lot of opportunities to meet girls-I couldn't help but feel that I was 'leaving him behind'. I would probably feel guilty, not to mention he has expressed zero interest in breaking up any time soon. I am so afraid of breaking up with him and seriously regretting it-or hurting him- but I keep having these pangs of a need for freedom. Is it unfair to break up with him just out of fickleness?