Great problem.............(boyfriend and home..).........?

i and my boyfreind went on hidingly talking..........through my phone to his mobile.......all late nights..........as my family is coservative so they dont allow this..............the problem is that..in his mobile bills...........his father got my number in late night calls..and the most recieving calls..........now that he called my father to his home and that told him to get this matter of afair off.................i dont want to have a breakup neither my boyfriend..............and my family dosent know much about my afair......i convinced them that nothing was of such sort........bt still my father called for telephone bills details..............and they would come soon .....and the boyfreinds number would also b printed in them...........what to do?.....................i bf is a mla's son and is trying his best to hide the number from the bills................but if it cannot b possible...and my father saw the numbers then what t do..........hw to convince him that whatever he is thinking is wrong or false...........help!!!