you haven't been with your ex for a long time...surely things have happened in between. Lot of things can change his mind to come back to you as well..not that i am saying ..that is what happened..but there is a possibility. And also there is a possibility that he does love you and in between he was busy..so busy that he couldn't keep in touch..but i doubt that if u really cared for person one would just completely ditch the person (i never cud understand that)...anyway... and with the current one well...even you are not sure enuff to go ahead with marriage...and of course i think 6mths is too less of a time to know for sure. I don't think choosing either one is good. Take your time and think about it some more.....this is your life after all. You'll be taking a chance if you go back to ur ex without knowing everything...not that he prolly will share everything that happened in between. With the current one i guess in time u'll know what you want.