What do you mean by "straight forward relationship"? Just tell them you cannot speak to them and do not speak to them. They'll leave you alone. Maintaining any sort of relationship with ghayr mahram women only leads to disaster. They may not know if they're doing anything. In fact, your "straight forward relationship" probably confuses them into thinking you're lax in your deen, even if you're really not and that is probably not the impression you want to give.