well even though he is your sister's past you shouldn't mess with him. there are so many other guys out there that havent dated your sister.. go find one of them. sister's should never date guys who their sisters went out with. those guys are just off limits. and put yourself in your sister's place would you like your sister to date one of your exes??? anywayz i know it's hard to get over a guy, but you could ruin your relationship or put a dent in your relationship with your sister, who will always be your sister. there is no guarantee that this guy will always be in your life so why mess anything up with your sister...
-Vanessa