Most Helpful Guy
Of course it is. Keep in mind that an ex has no obligation to their past, not even for the sake of sharing children except taking care of that child as a parent. Secondly, depending on what you two truly meant to each other matters. If he or she wasn't truthful then of course it's just as easy to let go and replace them.
Most Helpful Girl
I replaced my ex-boyfriend in a week. Two months seems like forever :/
Sorry about what happened... but moving on is your only option. Whether or not you two should have broken up and stuff isn't going to help you heal, and comparing yourself to his new girlfriend is only going to make you feel bad. You chose to end it, time to stick with your decision and look to the future. :)