try "no contact". no matter how much he bugs you through your common friends, don't give in to what he wants. Sometimes, when people end a relationship they feel guilty for hurting others and that's why they sometimes keep in touch. So no matter what he does, don't think that he still wants you back or anything cause you'll both just end up confused. Try to avoid anything that may go on between the two of you and see, after a while, if you really want to get back together.