oh gosh. i have dated few leo men before and they all got on my nerves or maybe i just met the wrong ones. ok from what i know about leo (the common traits i found so far) you will never find him alone. He will always be amongst a group of people and, more often than not, he will be the center of attention. and yes, that means he loves going out to socialize and partyyy. hwoever, they can be real sweethearts and that was when i let down my pride (hellooo i am a gemini too) and there were lots of romance involved. but when he's out, he can FORGET about you! They seem to be young at hearts too. but back to your problem, maybe you could initiate the moves first, maybe he's confused about how you feel or he feels about the relationship so they tend to distant away from you. they need lots of affections too, so when you're together how do you guys act?
anyway, if he still doesn't response to your efforts then might as well just move on. its just not worth it, else you will be losing yourself in a pursuit of attention and eventually getting hurt.